Framework agnostic state management

React requires you to break your UI into components, but plain JS apps can be structured in any way you see fit. Data for plain JS apps are stored in the DOM itself and has to be found from the DOM before it can be used. React apps store data in regular JavaScript variables.

Absolutely, yes . Without it, you’ll be plagued by bugs in your code which you can’t even begin to debug. JS frameworks and libraries will be a mystery. You might know just enough to scrape by, but you won’t have a good time developing.

Short answer: Yes, vanilla JavaScript is still being used .