You will most likely not find yourself in a position where you build a large scale project with the raw dom api, this is what people refer to when they say vanilla. There is no market for it, there never will be again. The dom is an implementation detail, there's almost no point even learning it, and it makes for a terrible choice for application development.

Frameworks come and go, some say, which also isn't entirely true, react is nearing 10 years, but paradigms last decades. If you don't know what mvc is, or view=fn(state) your chances of employment decrease, because these patterns represent pretty much our hardships and collective solutions.

There's nothing opposed to javascript otherwise when using a framework, you most likely just get better at it.