Agreed very much.

I'd extend this to "web apps that revolve around forms, views, filters and pagination" when it comes to "Ajax" stuff (yes, I'm old).

The part of htmx that's relevant to these topics being discussed here, I once wrote an inferior clone of, some years ago.

It was "isomorphic", tailored to our PHP-based CMS, and could handle filters, search forms, and pagination.

Suitable for forums definitely, and current PHP-based forum software vendors that are still on the market follow the same paradigm.