As someone who's been building against browser/web tech for over two decades now... that React is emphatically no less than "Good"... The diagnostic messages alone are leaps and bounds ahead of anything else I've used. Angular just breaks in weird ways with no warnings, sometimes non-sense error messages, other platforms likewise... React regularly warns on usage that might break something in the next release, and more than a clue how to fix it. Nothing else I've used comes close to that. Not that it was your implication.
Now, I'll admit, I've dev'd against React and deployed with preact-compat as a build sub for size... but a couple times back to React for broader support, and it really didn't save on speed anyway.
React is hands down the first web tech I've used (out of dozens of platforms and toolkits over the years) that just made sense. Not everything I agree with, and would love some adjustments. All the same, more often than not, it does what I expect, and I definitely can't say that of most of the rest.
As to jQuery, I think it's a great idea, was and still is in a lot of ways. I do wish they'd just drop their XHR, and Promise implementation at this point... but the selection library + eventing is cool and easier to grasp to this day, despite going without it for about 2 years now. There are cases where it was just nice, and still is.
I'm actually fine with JSX, imho it's better having some XML in my JS than it ever was having weird DSL in templates in JS.