You can still do JS on the client here and there, but that becomes much less needed.
...instead write it in htmx, and html partials server-side using a templating library. What could possibly be wrong with splitting up the presentation logic and spreading it throughout the backend instead of just writing a little bit of javascript?
One code base rather than two?
Simple pages become simple again?
AJAX philosophy was based around client side render - Asynchronous Javascript And XML. XML was JSON before JSON.
jQuery is/was just a fetching library. The modern fetch() API as well as Promises/async/await made it largely obsolete, although some people still swear by it (they just released a new version actually). You can fetch raw HTML and dump it into innerHTML, but thats not how most people use it. They would do client-side render based on the XML (later JSON) returned.
I assume the compiler can give warnings at compile time?