Depends what you mean by "the product". If the product is a content platform where the main purpose is serving ads, then I agree. If you're trying to build a "bicycle for the mind" that actually empowers the user then removing seldom used, but useful features will kill the thing. I can imagine what A/B tested Vim would look like.

>I can imagine what A/B tested Vim would look like.

Much more intuitive to learn?

A vim A/B test blindly adhered to would make it so any key pressed quit vim.

I want Clippy for Emacs. "It looks like you are trying do define a new mode. May I help with that?"

And then all it knows how to do is help you install Gentoo

in 3 commands

I disagree. Good product design is faithful and doesn't change every time someone does an A/B test