Well, obviously a text editor built on top of Lisp is going to be pretty good at editing Lisp-based languages like Clojure. Emacs is pretty poor at everything else though. I remember trying to get it to do even basic completions in C++ beyond hippie-style completions and it just couldn't do it no matter how many packages or servers it had to help it. That was some years ago though, but emacs develops slowly so I doubt it's changed.
That said, the tiling WM features it has are pretty good.
"LSP tooling" for Java/Kotlin/Scala doesn't exist as far as I'm aware. I'm sceptical about LSP stuff anyway. In an IDE performance and latency really matters. IntelliJ plugins have direct heap access to the AST and editors so they can rapidly explore the code, add annotations etc. Java adds some overhead but it gets lower every year, they just never stop optimising the JVM, and serialisation/context switching is gonna add a lot back. Especially as you'll really want to be writing language servers in high level languages anyway. There's no justification for writing such a thing in C++ or Rust.