I think the original concept of using inline styles in your React components was truly a leap forward in terms of styling DX. It seems like most of the developments since (CSS in JS, Tailwind) have just been more inefficient ways of implementing that core inline styles concept. Ok, these new solutions give you pseudo classes, but those can easily be replicated in JS. Beyond that, I don't see the upside of the additional complexity these solutions bring vs plain inline styles.