I am a very anti react person but I believe that HTMX alone isn't enough. The problem that React solves (and Svelte solves much more elegantly) is not that of reactivity etc but of being able to describe your UI in terms of components and then build your application from those lego blocks.
HTMX leaves that component problem to the server side templating instead and IMHO that is a far more loose and leaky abstraction.