who wants to use a polyfill forever?
Many frameworks implement around helpful things missing from the web platform itself. However, application frameworks will always have a place because I don’t think we’ll ever have enough consensus on one approach to building applications for some types of features application frameworks provide to be standardized and implemented in browsers — nor should we.
However, most modern frameworks don’t implement web components, so in this sense we’ve locked ourselves out of using web components in ways we could otherwise. Presumably this will change as the support becomes ubiquitous.