We absolutely don't have shared language for these things and we aren't always talking about the same things. The thing is there are just vanishingly few places where you only need a "sparkling of interactivity on top". Yes your blog probably doesn't need a full framework, nor does your news site (which is just a blog++) or your marketing web page. But so many other things really do or things break down quickly. Also what your web site needs today might not cover what it needs tomorrow. I've seen a number of "web admin"/backend control panels (customer-facing for config) start simple then grow until they start to collapse under their own weight with just added jQuery as needed. Sure, at the start, htmlx/jQuery might cover all you need but soon you are building custom UI to represent business logic/ideas and managing with that gets very unwieldy. The people that say "all you need is the built-in HTML elements" are living in a fantasy land, try using the default date/time picker and get back to me.
I'm sure there are things I'd agree with the anti-react crowd on (places you don't need a framework) but all their examples are incredibly contrived and feel like the "TODO app examples" you often see for frameworks or learning a language. They don't even scratch the surface of what's needed for complicated apps, they are great to show off the simple things but it seems like the anti-react/anti-framework crowd thinks those simple examples are all you need and that's just silly.
At the end of the day I'll admit I reach for a framework earlier than I absolutely need it and that's because I've built 10's and 10's of sites (web apps) from the ground up and eventually you either use a framework or you end up creating a shitty version of one. So yeah, day 1 I might not need Vue but day 100 I'm sure glad I have all of Vue to build on.