None of this is possible with HTMX if the user has JavaScript disabled. The first step to using HTMX is to import a JavaScript file from a CDN, and none of the features for partial page replacement will work without it. Whereas with Next.js, with JavaScript disabled, a Link will revert to a full page load where the next page is rendered on the server. It will be progressively enhanced to what appears to be a partial page load by using the same JavaScript that would render the full page on the server to instead render it on the client starting from the current state of the DOM.
Umm, progressive enhancement is a general concept that can be applied to any stack, not just Next.js. With htmx we can just use good old anchor and form tags to fall back to full-page loads if JavaScript is disabled. In fact it makes it more obvious because usually those are the tags we're using even with htmx and JavaScript enabled.
I write plenty of JS (12% of my biggest project, according to GitHub), but it's added onto HTML in such a way that the HTML still works for:
* a security-minded person who has it turned off in their browser,
* a user of a browser without JS support, such as Links, Lynx, w3m, Dillo,
* someone with an older device using NoScript for performance reasons,
* someone with a slow network connection who can't load the included library,
* a server operator who chooses to disable JS rendering/injection and serve plan HTML, such as the website for a Bitcoin conference,
* another scenario I haven't even thought of or imagined yet.
My conscience as a developer and enabler of information access just does not allow me to write off all these people as undeserving of accessing my websites. You may feel differently, and I think that is OK, too...