Well, there is webassembly, this will enable static programming languages like c, c++, and rust. Rust is high enough level that it’s a pretty good sell for web apps. Even so, once webassembly calms down, we can build alternative interpreters that run on it, and run Python/Go/Java/etc. in the web. This will not be quite as efficent, but as c is about 50% slower in webassembly than on native hardware, I think a Go/Java would run well, Python might be a bit behind, but Lua is simple enough it might work.
TLDR: You don’t have to kill JS to get those language functionalities, just wait for webassembly and all the cool stuff that comes about from that.
Caveat: Though I’m a developer, I’m not a webassembly developer. I’ve heard of these things as theoretical possibilities, but don’t know the specific limitations. Sounds promising but who knows how long it will take to get there.
I think I’ll take my IDE that has the choice in which AI assistant I get… Why would anyone lock themselves in like that?