pcthrowaway is more or less right. Tailwind dramatically improves code coverage. A majority of tailwind's common utilities are used in every page's components or templates.
There are exceptions. We could use postCSS to code-split critical paths for CSS. It sounds like a fun side project for some framework's ecosystem. Unfortunately, the current state of CSS is very much good enough for me for now. I'm much more concerned about main thread work from JavaScript and optimizing images for the web, for example.
