Personally, I think your thesis is wrong. There is no "new JS world created by libraries like React and Angular". JS is JS and will always stay JS, just as there have always been libraries and frameworks of any kind.
What you potentially might mean is the world of web development. But even then there is nothing new. There have always been many libraries which wanted to make stuff easier for people.
Personally, I don't really like most of the libraries we currently have, as they are way over-specialized, but at the same time tragically miss-used. It feels like...

Personally, I have seen need for neither of the mentioned frameworks and I prefer to stick to standards instead (for instance WebComponents). Read my full reasoning here.