Tailwind solves a somewhat different problem. It's maybe easiest to think of it as a bunch of aliases for writing inline styles. The fundamental problem with CSS at scale is leaky abstractions, right? Tailwind moves the abstractions down a level, so that rather than attaching semantic classes, you're just composing the properties of an element directly, except you don't have to remember if you used px or rem for this padding, or what the media query for a mobile breakpoint is. This tends to reduce the incidence of high-gravity classes which tend to accumulate features, at the cost of some verbosity vs something like Bootstrap, though it's significantly less verbose than equivalent inline styles would be.