[aridiculous]

The biggest issues I've had with Tailwind:

1) Adding it to an existing codebase with lots of global scope. The techniques espoused in the documentation simply don't work well with existing leaky CSS with varying levels of specificity. Adding important to all TW classes and name-spacing all of them invites new problems.

2) Making your own components with lots of variants: the syntax required feels like you're doing contortions to make it work nicely. There's probably some special techniques but it's a lot easier to take advantage of the cascade in my experience.

3) Dev tooling: the OP I think is dead-on in the criticism that you break a lot of browser tooling when using Tailwind. The right hand side of the Elements tab is a complete disaster. The JIT that Tailwind provides to only include styles you need also makes things annoying: If I want to add some classes on the fly in the Elements tab (which is annoying anyway by having to edit HTML), it won't work if you need any classes not currently not used in the built code. You can mitigate this with modifying your JIT setting for dev to include a ton of classes but it just doesn't flow. The TW documentation is very cagey about how dev flows should work and for good reason.

I actually like utility classes as a concept and if I were starting greenfield projects I might consider Tailwind with an existing component library despite the dev tooling issues. I just think it doesn't layer onto existing codebases well.

[CSSer]

1) My heart goes out to you here. I feel like re-adapting any existing styles to work in or with a new system can be a real challenge, and I'd hate to have to make it work. I've tried this once in an environment where it would have to mesh into a larger system with prefixes/important. I gave up and wrote vanilla. Tailwind just doesn't seem like a good fit there.

2) They have a couple of pseudo-selectors but just largely don't use them if we need the cascade. We just write vanilla instead, but it's funny how often that isn't required. When things need to be dynamic we'll often use the classnames library.

3) This is really interesting because we haven't really experienced this. I wonder if it's framework or ecosystem specific. I often find opinions vary broadly across these lines because of what you noted about the variance in dev flow.