Just to play devil's advocate, you may not see the advantage, because you already know about all of those options.
There's a fair amount of library discovery/evaluation overhead needed to get a fresh start in the React ecosystem, and the people who have to do it often don't have the perspective/context to make good choices efficiently.
I started learning react a few weeks ago and I've been using react-router and thinking about learning styled components or something similar. I have a few years of "experience" with toy <5000LoC "webapps".
I don't think they're that hard to discover, although I spent a while trying other Google searches before I realized react-training's react-router was the real router everyone mentions. Somehow their website seemed quite scammy, and I was very surprised routing wasn't in some sort of core/stdlib.
It's also important to note that not all developers have the same constraints.
If your employment prospects don't depend on using the major frameworks that everyone else is using, you're probably going to choose (or even create) a framework that best fits with the way you think and the way you like to work.
There's a fair amount of library discovery/evaluation overhead needed to get a fresh start in the React ecosystem, and the people who have to do it often don't have the perspective/context to make good choices efficiently.