It's a case of Chesterton's fence. Having built complex apps pre-react, I wouldn't be in a hurry to go back to that approach because I have first hand experience of running into the problems it solves.

React is a paradigm change (from imperative to functional) that makes sense in a large UI project. React itself is fairly small in terms of deps.

The main issue is the tooling. JSX is nice enough (not required though) to want a transpiler that will also bundle you app. It’s from that point things get crazy. They want the transpiler to also be a bundler so that it manages their css as well. They also want it to do minification and dead code elimination. They want it to support npm dependencies,etc…

This is how you get weird ecosystems.