I mean having to jump between the HTML and multiple CSS files (which often you have to track down by using the browser inspector) to make edits to while styling things. When HTML and styling are tightly coupled anyway and almost always edited together, it just slow everything down for no good reason vs co-locating them together via utility classes.

> The cascading part means you can always add in a file after and overwrite it. I don't see how this would get better without the cascading part.

If you mean overwriting styles set somewhere else, this is what makes CSS confusing and hard to refactor. Cascading is just best avoided whenever you can.

> I am happy to learn new languages if there are clear benefits.

I can recommend looking at Tailwind. Make sure to use it with some kind of templating language e.g. so a "button" component goes in a template file, as that's the way you reuse styling (vs copy/paste) which critics seem to miss. It makes styling much simpler and quicker (everything is co-located, no need to write selectors, no need to make up class names, very concise syntax especially for mobile), especially if you're doing complex responsive designs.