I'd say: everyone thinks they know javascript. Learning a new language is easy (especially with C-like syntax) but not the library. The language having nearly zero standard library makes it change under your feet on every different context. Deno started the initiative to supply what you get in the browser everywhere, but the browser being a GUI environment, the missing stuff need to come from somewhere, like the Deno.listen[0]. .NET is not much better with one million different runtimes with different platform support and capabilities.
Now, if I do need a lot of interactivity in the frontend, I use Inertia with Laravel, which gives me a real full stack, robust, battle tested, well integrated and very productive solution.
I do - .NET (since 5) has been great. And you've got stuff like Blazor for the frontend if you want to avoid JS entirely.