The appeal is literally a "fuck you" to anyone that makes me have to run a build process for a web page, when I used to just be able to click reload and see the reality in front of me in seconds on a machine 1/500th the speed.

You can drop react into an html page with a script tag. You don't need a build step. The build step is only requisite if you'd like the full benefits of react, which personally I find worth it. Cached builds are quite fast. All build steps/compilers/etc. exist to add some devex upgrade on top of some lighter-weight thing that many devs find useful.