Does Ruby have an ORM/HTTP request handler/URL router in the standard library?
I am not sure I follow the analogy. If all you are taking from tailwind is the utility classes, fine. This is the part that provides value. But tailwind is not just that, is it?
Rails is a fully formed opinion on how you should write a web app in Ruby and all the various technical components you need to fully realize that opinion.
Tailwind is a fully formed opinion on how to use CSS (utility classes etc.) and all the various technical components you need to fully realize that opinion.
Thinking of Tailwind as just a bunch of regular CSS utility components is misunderstanding the scope of the project. That alone has a lot of tradeoffs and compromises - the file size is absurd and you can't bundle things into components, you also can't have arbitrary values in the utility classes. It wouldn't be a complete opinion on 'the best way to use utility classes', or however you want to frame Tailwind.
I am not sure I follow the analogy. If all you are taking from tailwind is the utility classes, fine. This is the part that provides value. But tailwind is not just that, is it?