It found its place because working on CSS on any non-trivial scale with multiple engineers is painful. The best way to deal with CSS at scale is not to write CSS. And this comes from me who really likes CSS.

Oh why can't this idea die, it has been continuously debunked for 6 years now. So much so, any TW discussion will reiterate it.

It's inline CSS, but with all the limitations of inline styles removed. There is a lot of stuff that can't be done with inline styles, like media queries.

It was/is inline styles, not inline CSS. It isn't a stylesheet at all, just a single style property.

It is used because UI component frameworks make vanilla CSS an awkward an unnecessary tool (the Cascading part). CSS makes sense as designed for styling a document, but not so much for styling atomic components. If we were designing the web and CSS from scratch around the React model, CSS would not be made to cascade, because that is totally unnecessary and usually leads to more issues than it solves. Apart from theme variables, in a component system there's no reason to have global CSS anywhere; you'd just style each component in isolation. So when in the React model you typically want no cascades at all, the library that is made for that gets popular.

CSS modules are also a solution to the above, but, once you get rid of cascading, and you have one stylesheet per component, it is again unnecessary to have the one stylesheet in a different file from the one component. There's no benefit to splitting a component and its styles into two files; it just makes it more annoying to edit. So we move the styles essentially inline, with either Tailwind or CSS-in-JS.

That, plus it looks like Forth code

    grid dup 1.0 scale wind-x drop cols-4

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I think it is mostly backend dev who don't want to spend time in frontend stuff.