React+Flux can do in just 137 lines what jQuery can do in 10

Kinda linkbaity. As commenters in the article pointed out, the jQuery code omits the HTML and the React port has some functionality that is not present in the jQuery version, so the LOC comparison in the title is pretty meaningless.

The conclusion is that for a tiny one-off tool that can be banged out in 20 minutes, a big framework like React/Flux is completely overkill. But for large codebases where maintainability is a big issue, then React/Flux can be extremely useful (considering that's exactly the problem React/Flux try to address).

Am I the only one who thinks this stuff ought to be obvious?

I think this blog post is pointless. Of course every abstraction adds some overhead at first. If your problem is simple enough to fit in a few lines of code you don't have to think a lot how you structure it.