HTML, css, JS (jquery) have stable APIs, when new developers come they don't have to learn something new.

If your code degrade over time, sorry to tell you, a framework won't solve the problem.

If you have coders that don't care about maintainability of code correction, code organization in whatever technology, they won't care about what you wish.

As usual, they won't take the time to learn the frameworks, will diverge, and you are back to square one with no code that can be salvaged or reused. (at least with vanilla techs you may salvage stuffs)

I think you use frameworks to solve the wrong problems here: you are probably the problem by trying to ditch the lack of real engineering skills in IT (not the letter of engineering. The spirit: making things that are correctly built and are reliable over time... like a plane).