What is the problem with the DOM? One of the most reasonable thing's I've heard is that the DOM does have side-effects. That's not really relevant outside of a functional approach but react insist on being functional so
A to A' obviously seams important the idea was to have no sideffects and a predictable mutation pattern. There is ofc some BS involved but luckily most devs are "users".
So in most cases I personally would stay declarative (HTML) with minimalistic CSS. because I don't need a rocket engine behind everything.
But as soon as my layout uses non synchronous update cycles so for example I have a component in the layout that should update on a dropdown change. The app-state to render-state issue is slowly starting to arise.
This is where react for example could come handy. I personally think it's still to bloated for such a simple task but the reasoning is more sensible. As soon as the page is not contained into 1 single Request and Response people tend to get confused.
The question of when a framework makes sense is like everywhere 1st usecase. It's always the question what we're trading. Do we need to know all cycles of updates? do we need to understand how an event really bubbles?
In my opinion based on my observations a lot of the modern JS-devs are framework users, they have to deliver and deliver and deliver so they try to push the thinking to their tools. that's what Gabor for example said "focus on the business-logic".
In my opinion, if you don't have a page that needs to be highly interactive .... you have to be an unexperienced programmer or you have way to much time, to add anything complex to your frontend as a complete framework.
But as soon as interactive asynchronous state changes / reactive state changes are necessary you probably have to much time or you are a classic old dog to not at least consider using a modern frontend solution for that.
I hope I am not to much off topic with my answer :)