Except for the genders, which are completely arbitrary and very annoying to a learner.

This is because English has lost most of its Indo-European heritage (except lexical), and looks much more similar to Chinese that to an IE language like German, Spanish, Russian, Greek, Hindi / Urdu, or even Farsi (though Farsi has also lost grammatical gender).

* English has no inflections; nouns and adjectives stay the same no matter what role in a sentence do they have.

* English has no noun-adjective agreement, and a very rudimentary verb-noun agreement (only third person singular).

* English words have unpredictable pronunciation: like in Chinese, there are some hints and rules, but they are full of exceptions. Try to find a pattern: "busy" / "Suzy" / "circusy", "corps" / "thorps", etc. No way to predict the sound without knowing both the etymology and tradition.

* English has no grammatical gender.

* Though unlike Chinese, English has a sharp distinction between singular and plural.

No wonder even German looks somehow distant from English :)

Oh those things are certainly true, but the genders are not consistent across Indo-European languages. In learning a language they act as a thing to get stuck on. It's an unpleasant feeling to know you are constantly getting genders wrong, even if you are understood (though seemingly in France, getting genders wrong is sufficient to be not understood).

Although vaguely off topic, one thing that grinds my gears is calling Persian "Farsi". Nobody goes around saying "hello I speak Español" but for some reason, rather recently, it has become popular to use the endonym for Persian in place of the already well established "Persian". I've more than once met people not knowing they are the same thing which is sad because using the new word loses well-rooted associations like with famous authors and other cultural elements etc

There are several persian languages, so referring to the one you mean as "Farsi" makes it more clear (as opposed to "Tajiki" or "Dari" for example).

That's an afterthought, in English you say Levantine Arabic or Egyptian Arabic, or Brazilian Portuguese, Bavarian etc not "Bayrisch" or "al-lahje shamiye" or something else

English has had a lot of good or at least interesting evolutionary reasons to drop most grammatical cases and grammatical genders. English decided to make some interesting trade-offs in expected word order to lower redundancy in inter-word agreement morphology.

Also, while Proto-Indo-European had plenty of grammatical cases, the current theories are that it had fewer grammatical genders than modern languages. The PIE grammatical genders are generally attributed as "animate" and "neuter" and there's a lot of interesting debate on exactly where and when (and why) what today are called "masculine" and "feminine" split from animate (and how much they were "masculine" and "feminine" to PIE is also an interesting debate). That split might have been very late indeed, which seems reflected in the evidence of how few Indo-European languages agree on grammatical genders beyond people and a very small list of animals. (Also, late enough that for instance Farsi might not have "lost" much at all, simply missed out on some of the late splits and evolved around them.) Grammatical gender especially has stopped being seen as a key common trait in IE languages given what linguists have seemed to reconstruct of PIE.

> No wonder even German looks somehow distant from English

A lot of that is inter-tribal politics more than just the syntactic shifts English experienced versus "trunk Indo-European". Modern German sometimes referred to as "High German" intentionally dominated in such a way as to push out all of its "Low German" rivals from the core of Germany which included the Anglo-Saxon tribes. At a raw level English is closer on the family tree to other "Low German" languages such as modern-day Dutch, but modern-day Dutch has its own cultural supremacy battles in its territories and mostly driven its rivals to extinction, several of which themselves were closer to English on the family tree. The closest living relatives of Anglo-Saxon German are the Frisian languages [1] most of which have been classified as endangered or nearly extinct due to cultural domination fights with Dutch (including events relatively similar to the Norman conquest in terms of massive linguistic after-shocks, just between Dutch and Frisian tribes). Modern English is like four tree-branches away from Modern German, even before taking into account the Norman invasion influenced language changes and slowly differently evolved syntax. So it shouldn't be a surprise English looks distant to German because it was always distant to German.

[1] https://en.wikipedia.org/wiki/Frisian_languages

Thanks for the detailed comment!

Certainly there are languages more closely related to English, like Dutch or Swedish / Norwegian, that stand sort of midway between English and (High) German. But if we take older languages, like classic Latin, or those with many archaic features, like Lithuanian, the distance from English syntax and grammar becomes pretty large.

I suspect that languages tend to simplify in grammar in areas where several different languages have to coexist: say, England had Germanic, Celtic, and French languages interacting for quite some time, with some Latin thrown in by the church.

I suspect that Mandarin Chinese also resulted from many languages on a pretty large territory interacting a lot, shaving grammatical complexity bit by bit.

English's grammar didn't simplify if you mean its syntax by that, its morphology did. (Inflections affect morphology [word form] more than syntax.)

English's grammar actually got far more complex because word order matters a whole lot more syntactically versus German or French or Latin. For one big instance that is often pointed out by English as a Second Language problems, adjective order in English is comparatively extremely rigid: https://en.wikipedia.org/wiki/Adjective#Order

Another place you see this complexity is the old "sentences should not end in a preposition" early schooling "rule": in Latin word order mostly doesn't matter as long as key things agree on grammatical case/gender. Prepositions "can't" syntactically exist in Latin without their paired nouns inflected to the right grammar case. But the pair itself can be in almost any order in the sentence. Whereas English has a more rigid prepositional word order, because nouns don't inflect at all when used in a preposition (unless you are someone still trying to keep "whom" on life support centuries after it died in English and became a grammatical zombie). The syntax is more complicated, but the morphology is easier. One of the interesting "gains" from the complicated syntax is that some prepositions started working with intentionally dropped or elided direct nouns. That is also added syntactical complexity. In English there are many prepositions it is perfectly valid to end a sentence with. Parsing that is interestingly complex.

Extremely relatedly the similar childhood "rule" to "never split an infinitive". In many languages infinitives are a pure grammatical case involving word inflections that have to match, and the order generally doesn't matter if they involve multiple participles, and there is no such thing syntactically as a "split infinitive", it just can't syntactically exist. Whereas English relies on a more complex syntax for infinitives that relies more explicitly on rigid word orders, making split infinitives at all possible in the first place. Then regular usage of the different concurrent syntaxes started to diverge their meaning. "To boldly go" means something subtly different in English than "to go boldly", and forbidding split infinitives entirely forbids entire categories of creative expression in the language.

I don't think there's a simple answer for why English grammar evolved the way that it did in shifting morphological complexity for syntactical complexity. I just know that calling that evolution "simplifying" isn't entirely accurate either. (English syntax feels simpler to native speakers than it actually is.) The language certainly had some interesting linguistic pressures being confined to a highly regarded/desirable set of isles for centuries with a mixture of strong related languages immediately nearby, then when it was used as a language for helping bootstrap an industrial revolution and as a world-spanning empire.

Indeed, for a native English person who doesn't have genders for inanimate objects (I'm sure someone will come up with an exception) they don't seem to add any benefit. La chaise vs Le chaise. It's a chair, you sit on it. Someone articistic might decide that a chair has a masculine form, but another chair could be feminine, but that doesn't change the "le" vs "la" part.

Do non-european languages have genders?

yes, and/or word classes that may involve Gender, animate/inanmate categories, etc.