[setr]

The trouble generally is that JS is used despite the content being static, or independent of client behavior/usage.

That is, JS can be used to do everything but it is not optimal, or even near optimal (or even remotely close to) for many use cases. In terms of runtime or simplicity. But because it is capable and available, it has encroached into every niche (of html/css) until like any invasive species, it consumes and shreds through all available resources, collapses the whole ecosystem, and all complex creatures give way to a fresh start with new fairly rudimentary biology (wasm) trying to evolve towards and find a new stability point — hopefully one that does not invite a similar destructive species, but we’ll see how it goes

[genericstorage3]

For example you can do a drop down menu in css. Then you have some new requirements that css alone can't do it.

Even a basic thing, could be impossible in css.

All your css logic goes to trash. Or you can keep css logic and make a mess of a software

If you have done it in js, you'd be able to reuse some code.