On the other hand, from my experience, large development teams cannot write CSS at scale. "Writing clean CSS code" doesn't seem to be a skill that most (frontend) developers seem to value, so abstractions like CSS Modules (which is barely an abstraction - it's just compile-time BEM) and CSS-in-JS came up to manage complexity of both a large codebase and large team.
On the other hand, scaling CSS is fundamentally hard especially in a large team where it's more of an organizational problem.
It takes eternal vigilance to maintain it. Refactoring it is a huge feat. And when you want to modify or add a single component, it doesn't make sense to re-cred in the whole CSS apparatus, and it's not necessarily trivial to figure out where to make the CSS change, so CSS files tend to become append-only.
It's like how learning how to "write clean code" doesn't really change much about how hard it is to change large software systems over time in a large team.
