We have utility libraries, class-naming conventions, and methodologies dressed up in framework branding. What we don't have is a CSS layer that behaves like a framework does in any other ecosystem: typed input, defined output, a contract a compiler can actually enforce.
This is the long version of a complaint I've been making in private for years. It also names what I think a real CSS framework would do, and shows the working sketch I've been building in that direction.
Tailwind is automated OOCSS
The current heavyweight is Tailwind, so let's start with what it actually is. Strip the build step away and the utility-first methodology isn't new. Object-Oriented CSS, popularized by Nicole Sullivan in 2008, was already making the same case: small, single-purpose classes you compose at the markup layer.
Before Tailwind existed, plenty of teams generated their own utility scales using SCSS loops. You can rebuild a meaningful slice of Tailwind's spacing and flex utilities in a few lines of SCSS that would've worked in 2012:
