It's hard to answer because I don't personally use HTMX as a way to avoid Javascript. HTMX is a Javascript library. And I don't know if I even find using HTMX easier/harder than writing JS, because they are fundamentally different approaches to building apps. It really just depends on what I'm trying to do.

One is a programming language used for writing client side code, and the other is a minimal library that makes server sent documents more ergonomic. Yes, it's a JS library with a few nice conveniences, but the main draw of HTMX encourages a completely different app architecture than what the average dev would arrive at with plain JS.

They're just two different things to me, and so it seems irrelevant if LLMs can help you write one faster. If you're only using HTMX to avoid JS, I don't see how LLMs discourage you from doing that. Wouldn't it be better to vibecode something you have an easier time reading than vibecode a language you don't even understand enough to use? What are you going to do if it blows up?