Why is React or Angular so categorically required in the work?

Question

React

Good evening, tell me why knowledge of React or Angular is so urgently required?
What is it about them that after them pure js is treated with disdain?

Answer 1

In general, there is nothing "such" there. If you are developing a project more complex than a static business card site, you need an architecture. You can, of course, come up with everything yourself on "pure js", but it will either be complete nonsense, or not commensurately more expensive than just taking a ready-made "framework". And how will you then explain to the developer who came to replace you what, why and how it was done.
And if the project is written in angular\react\yourFrameworkName, then the corresponding developer will somehow figure it out without anyone's help