I agree with you somewhat, I wrote a blog post called "Use 98% TailwindCSS, 2% plain CSS"[1]. I have recently been making an effort of making dark/light themes work and the problem increases again: it's a bit too easy to forget a set of qualifiers. I know that a number of libraries attempt to create "smart" class combination functions, so maybe the best solution is somewhere in that direction.

[1]: https://kristiandupont.medium.com/tailwindcss-an-update-b88e...