Overcomplicated type system. Language server seems redundant to mention, everything has a language server. Everything has ide integration. Everything has decent compiler feedback. Everything has hot reloading.

yes some languages have them, no they're not as good.

Pretty much all major languages have all of those features save hot-reloading, but that only even makes sense for UI written in an interpreted language.

There's hot reloading in .NET and Java

What is the use case for either of those two languages?

Being able to update the code while it's running is useful for all kinds of use cases. Desktop apps, web apis, server side rendered web apps, .net blazor apps, etc.

It's nice to be able to see what your changes do without rebuild and restart.