The absolute most important thing in ReactRouter does indeed boil down to what you said, no disagreement. But there are some niceties, if I'm not mistaken.
You want the things in your app that look like links to have some interesting behaviour. They should look like links, they should act like links when right-clicked.... but when left-clicked, they should not actually load the new page. Instead, they should update the History and also trigger the router to reconsider the routing. That's why ReactRouter includes Links and Redirects.
I suspect there's at least one other feature-of-some-utility in it that I can't think of right now. Hmn.
There's also some weird logic around multi-routing, which I suspect is a bug rather than a feature, but maybe there's a sweet use-case. And there's also some weird stuff about not propagating children, which seems like a bug not a feature, but the workaround is easy, and again maybe there's actually a good reason, I dunno.
Anyway, as with what you talked about, this isn't rocket science, you could do it yourself with some work. But if someone follows your advice and thinks that's the end of it, they'll eventually feel some minor pain points.
That said, I honestly can't be bothered to actually properly learn React Router. I think that some company, ideally one specializing in react training, should write better documentation for it.