I'm not really understanding what hyperscript brings. It's neither back end nor JavaScript, and only AppleScript users will be comfortable in it. It seems like just another library that needs to stay current with the DOM and might become brittle.
It’s basically another framework that lets you add interactivity to server side generated HTML views, ala Stimulus, Knockout, etc.
A lot of devs like approaches like this because they can do more with their server-side language and frameworks that they’re used to/more familiar with, since trying to do everything server-side doesn’t give you the interactivity UX, product, etc wants.
(I personally prefer client side HTML view rendering like React, and only talking to the backend via API calls, but I understand the use case for this sometimes)
htmx is a little different in that its focus is on extending HTML as a hypermedium, exchanging html (rather than some other data format) with the server, and staying within the original web network architecture articulated by Roy Fielding:
the idea with hyperscript is to provide a general, event oriented language that can be embedded cleanly directly in HTML
normal on* attributes are fine, but they aren't general (e.g. htmx fires a bunch of events you might want to hook into, and you can't use normal on* attributes to cathc them)
hyperscript also has a lot of features that are DOM oriented (e.g. query literals like <div.foo/>)
certainly not everyone's cup of tea, but it dovetails nicely with htmx and fills a need for a general, event oriented scripting language to complement it