The reality of React is that you have to keep re-learning and un-learning stuff if you want to keep up with React's ecosystem, because the surface area of the libraries is so large. (see "JavaScript fatigue")
Whereas with HTMX you learn a very, very basic concept in 15mins, and you're good to go for the next decade(s), and it will be more than enough for 80% of your projects.
Same as with vim and Emacs vs. proprietary IDEs and text editors.
I agree that people often do this but I don't think you _have_ to. You could have freely ignored SSR, RSC, etc. and kept on making boring old React SPAs. The churn is largely opt-in.