At all.
Every time web sites reimplement basic browser behavior, which they invariably do these days, they get worse, often significantly, because they never get it right.
I think you are overestimating how much 'UI standards' have gone up over time, actually. Nobody except for a small 'extremely online' set of people and control-freak designers care about all those complex UI/UX requirements. Users certainly don't care. They want fast-loading, responsive pages that get out of the way and don't drain their batteries or clog up their connection.
The other thing here is that approximately no one can actually tackle the complexity introduced by SPA frameworks and 'UI standards', and it's far more likely that they bungle it up and make giant, wasteful, UX pitfall-ridden apps. With server rendered pages, plain old HTML, and progressive enhancement, we at least have a better chance of producing something usable.
for the other stuff, the growing browser stdlib has basically replaced most of jquery's usecases. so (in the most non condescending or negative way possible) htmx occupies a very awkward sliver between "The Platform" and Frameworkland and after giving it some time I have yet to see the benefit from keeping any of it in my head