Naming things involves creating an ontology that makes sense. In the context of URLs, that’s an hierarchical structure of things that’s self-describing; in the context of code, it’s a direct model of the domain logic underlying the problem, at least for the most part: There’s lots of code involving "managers" and "containers" and "controllers" and "factories". That’s where it starts to get murky. Meanwhile, CSS classes require creating an ontology of things that’s both reusable, and at the same time referring to small or partial aspects of a thing, sometimes a thing that shows up in other parts of the code, sometimes as a variation, or just a one-off occurrence. If you do it properly, that means you’ll need to find a shared vocabulary for button attachments, centered max width wrappers, field hints, list items, and so on. It’s draining, because it’s not productive. The end result is just hopefully maintainable style sheets.
It's draining because you're over-complicating things. CSS is for styling HTML. So however you structure your HTML, CSS closely follows (hierarchy of components/partials). Then you consider variants. After that, parents influencing children styles. Then on top of that, you add a reset (because small browser incompatibilities) and maybe a grid utility.
