

Time isn’t the only factor for adoption. Between the adoption of IPv4 and IPv6, the networking stack shifted away from network companies like Novell to the OSes like Windows, which delayed IPv6 support until Vista.
When IPv4 was adopted, the networking industry was a competitive space. When IPv6 came around, it was becoming stagnant, much like Internet Explorer. It wasn’t until Windows Vista that IPv6 became an option, Windows 7 for professionals to consider it, and another few years later for it to actually deployable in a secure manner (and that’s still questionable).
Most IT support and developers can even play with IPv6 during the early 2000s because our operating systems and network stacks didn’t support it. Meanwhile, there was a boom of Internet connected devices that only supported IPv4. There are a few other things that affected adoption, but it really was a pretty bad time for IPv6 migration. It’s a little better now, but “better” still isn’t very good.
You’re not wrong.
Realistically, there’s a bit of a nuance. Many modern web apps have different components that aren’t HTML. You don’t need HTML for a component. And those non-HTML components can provide the consistency they need. Sometimes, that’s consistency for how to get the data. Sometimes, that’s consistency for how to display the data. For displaying, each component basically has its own CSS, but it doesn’t need to. A CSS class isn’t required.
Tailwind isn’t meant to be a component system, It’s meant to supplement one. If you’re writing CSS’s components, it looks horrible. If you’re writing components at CSS that needs a foundation of best practices, it works pretty decent. They’re still consistency. They’re still components. They’re just not centered around HTML/CSS anymore. It doesn’t have to be.
Sematically, it is still worse HTML. Realistically, it’s often faster to iterate on, easier to avoid breakage: especially as the project becomes larger. Combine that with the code being more easily copied and pasted. It can be a tough combo to beat. It’s probably just a stepping stone to whatever’s next.