Nope we don’t, but it solves a lot of the problems people frequently encounter while building web pages without too much of a downside. It’s a big trade off space and react sits in a very nice spot in that space.
Phenomenal answer. No, you don't need it, but if you build something long enough you'll avoid a couple categories of common problems by starting with it (and choose a different set of common problems)
I like to think about framework choices as choosing which kind of problems you are okay with experiencing. This choice can be made from a product perspective much easier