Comment by Induane

There are a couple of things:

1. Locality of behavior - the classes are the description of the style once you know tailwind, and they live where the thing they're styling is. I can look at a template and know pretty well how it is going to look without having to go lookup a sites personal bespoke CSS and match what's written there to the markup.

2. It's the same classes as you move from project to project. I have tons of small one-off apps I maintain, all using tailwind and I don't have to figure out the custom CSS classes and their meanings. It is a knowledge set that reduces friction between projects and I really need things that reduce cognitive load like that.

3. No dead CSS. There are tools to help with this in regular CSS but I just don't have to think about it with tailwind and that's nice. I work on my templates and the CSS is updated and minifed on the fly without extra steps (or unnecessary CSS).

4. Easy to build a personal component library that doesn't also require relevant CSS to be bundles with it. For me this one is pretty great. Thanks to template engines (for me it's Django's, but Jinja or others are grand too) I have a simple place to pull components (really just template partials) and widgets I've made and they just work because the underlying classes are the same. There are some exceptions around color schemes and the like but now all my little components take a colour scheme arg and voila, no proballo.

I think the key here is that a description of the visual is embedded in the markup. That lets the actual mark-up delivered to the front-end describe pretty much the whole kit. With server-side rendering ( I use HTMX ) I can even write unittests that responses contain expected markup, including CSS classes (I built a few helper assertions that all of my test suites use) which gives me some interesting checks.

I really ultimately don't think there is one correct way to do things. The things I value may be utterly irrelevant to another developer.