Have you tried it in earnest on a project? I was of the same opinion but once you try it (with VS Code and Tailwind plugin) it's hard not to fall in love with the ultra fast feedback loop and well defined colour palette.
Creating a "well defined color palette" is usually a part of the design-process when creating a new application/website. I understand that some people prefer the Bootstrap-process of already having a bunch of colors defined for you up front, but it certainly doesn't suit every project.
Plus personally, I don't miss the times when Bootstrap was trendy and every website basically looked the same. I like the individuality of the framework-less web.
You can easily do this in tailwind.
At the very least it should save a step or two compared to building the design system out yourself in a new project