When all I want to do is read content, no JS is needed. That has been a solved problem for decades. UX is problematic because now you have these huge PC screens and comparatively tiny mobile screens to account for. Most developers go for mobile first and completely ignore the rest, so you have loads of sites that are needlessly displayed like slow powerpoint presentations, autoscrolling to the next anchor because that’s “good UX” somehow.
Form validation with JS goes back decades and no one in their right minds relies entirely on frontend validation. It’s great because it can be immediate, but it’s easier to sidestep either by accident or on purpose. Since a lot of forms nowadays are “autogenerated” from their respective UI libraries, they come with a lot of unnecessary cruft.
meaning I can offer my app as a single HTML file you can download and use however you want
I sure hope that doesn’t need a “local server” of any sort to work. It’s one of the things that baffles me the most, javascript that only works with a npm server to connect to. I also hope it’s not bundled as an electron app, what’s the point of having an entire chrome browser bundled just to run a single page?