I've been writing CSS since 2000 (when it was introduced). I'm not a ninja, but I know how to write it, and I love Tailwind.

Tailwind is not for "people who don't know CSS", it's a design system. A value prop of it is for teams who don't have a dedicated designer. Tailwind gives you a set of fixed "design decisions" in the form of utility classes, which is far more flexible than something like Bootstrap, while still offering set constraints (which brings uniformity).

I'd even argue Tailwind is challenging and obtuse if you aren't already quite comfortable with css.

Exactly. Definitely wouldn't use tailwind without a firm css understanding first.

Tailwind is not a replacement for CSS; it is a replacement for tedious, unnecessary toil that comes with naming, cross-referencing, and coupling HTML elements to CSS classes. In a world of web components, Angular, React, Vue, etc. there is no longer a need to separate styles from their components; refactoring your application such that components encapsulate their own style is a good thing.

I believe you still have to do some "cross-referencing, and coupling HTML elements to CSS classes" when using tailwind. The naming and creation of those classes is what the framework provides.

That you think Tailwind is a "layer of abstraction"—it's not—suggests you don't know what it is and haven't made much of an attempt to find out.

Your idea of CSS is not simple. It's slow, it doesn't scale well, it's difficult to refactor, and it's a higher level of abstraction than Tailwind.

And why is learning CSS mutually exclusive with learning Tailwind? Tailwind is literally just abbreviated CSS properties and some nice tooling.

CSS is the base - it cannot be an abstraction layer of something that relies on that.

Except you're not actually talking about CSS. You're talking about CSS + a high-abstraction methodology.

Everyone who uses CSS uses a methodology, and that methodology comes with its own abstractions. For example, Tailwind is low abstraction; all you need to learn is how the config works and naming, which is relatively intuitive and can be learned in a day or two. After that you're dealing with mostly straight CSS properties.

Most methodologies people actually use when they implement "vanilla CSS" or SASS impose a high level of abstraction—naming, which classes do what, which classes map to which elements, how the DOM hierarchy must be structured, etc. Just because these things aren't necessarily committed to code anywhere (yikes) doesn't mean there's not a complex abstraction layer.

You seem to be convinced that Tailwind can be used without CSS knowledge. I just hope I'll never have to manage a project that took such statement serious.