HTMX is indeed simple and lean, but unfortunately that doesn't mean solving common frontend problems with HTMX is simple either. After a decade of frontend dev and being tired of react/vue/etc, I tried HTMX, wanting for something leaner, but IMHO it has big problems, and I am back to react/vue.
The two biggest problems with HTMX is that being fully server side controlled you need to put the whole app state in the URL and that quickly becomes a nightmare.
The other is that the code of components is split in two, the part that is rendered on the first time, and the endpoint that returns the updated result. You need a lot of discipline to prevent it from turning that into a mess.
The final nail on the coffin for me was that the thing I wanted to avoid by picking HTMX; making a rest api to separate the frontend and the backend, was actually a good thing to have. After a while I was missing the clean and unbreakable separation of the back and front. Making the rest api was very quickly done, and the frontend was quicker to write as a result. So HTMX ended up slower than react / vue. Nowadays react/vue provide server side rendering as well so i'm not sure what Htmx has to bring.
The two biggest problems with HTMX is that being fully server side controlled you need to put the whole app state in the URL and that quickly becomes a nightmare.
The other is that the code of components is split in two, the part that is rendered on the first time, and the endpoint that returns the updated result. You need a lot of discipline to prevent it from turning that into a mess.
The final nail on the coffin for me was that the thing I wanted to avoid by picking HTMX; making a rest api to separate the frontend and the backend, was actually a good thing to have. After a while I was missing the clean and unbreakable separation of the back and front. Making the rest api was very quickly done, and the frontend was quicker to write as a result. So HTMX ended up slower than react / vue. Nowadays react/vue provide server side rendering as well so i'm not sure what Htmx has to bring.