Sounds like we're agreeing with each other and disagreeing with the big SPA framework guy?
And, while only a minority of projects are that complex, those projects are the ones most developers are working on. Most other projects are probably better served with a wordpress install and a bit of theme customisation. Which means it's going to be a minority of developers who work with the very minimal things that are sufficient in these sorts of cases.
I've used SPA frameworks, but try to avoid it if I can, because most of the logic is in the backend. I don't want to create and sync API interfaces, have 1-2 additional contexts (JS + frontend framework) and debug an extra layer.
With htmx I can now have interactivity via the backend. I use Alpine.js for some interactivity.