These tools are absolutely nothing like React. Take a look at what htmx does, which is even simpler from a spec standpoint. There are actual on-going efforts to get it into the actual HTML spec. htmx and the like are basically built for us old-skool types (and thankfully many youngins are catching on).
Glad I'm not the only one. Ever since the first HTMX article, I felt like I was kidding myself. I had/have this thought in my head that "no way that we were that close to having all this right 25 years ago." I'm coming around and seeing that this tech gets the job done by doing one thing really well, and the whole API around it is dead-simple and bulletproof because of it. It's that good-old UNIX philosophy that's the enabling tech here.
While I can't say for certain that IE6 or early Firefox could have handled DOM swaps gracefully without real shadow DOM support, early Ajax provided the basic nuts-and-bolts to do all of this. So, why haven't we seen partial page updates as a formalism, sooner?
Not sure what you mean by so much more code. Datastar seems to do more than htmx. Otherwise, there are less features because React and friends over-complicate things for the vast majority of use-cases.
Ohhhhh I thought you meant simpler than React, lol. Gotcha. I was going by what it does, not line of code of the implementation, which is what matters in this context (a skeptic looking to check something out quickly).