As an emacs user I have to say that IntelliJ (and pretty much any modern IDE) feels snappier than emacs configured to do anything comparable (lsp-mode/eglot, corfu/company, tree-sitter etc).
While IDEs may require more resources, they usually utilize them better.
Emacs is fundamentally single-threaded and not great at async things. With most of the logic written in a very slow non-JIT friendly language with naive blocking GC. Rendering pipeline is also a mess. Underlying internal datastructures are also very naive (which is a good thing when you implement things in C).
Things are slowly changing. emacs now is a lot better than 5 years. So may be in 10 years it will really rival more modern competitors in terms of performance.
Having said all this, emacs universality and extensibility keep me with it.
While IDEs may require more resources, they usually utilize them better.
Emacs is fundamentally single-threaded and not great at async things. With most of the logic written in a very slow non-JIT friendly language with naive blocking GC. Rendering pipeline is also a mess. Underlying internal datastructures are also very naive (which is a good thing when you implement things in C).
Things are slowly changing. emacs now is a lot better than 5 years. So may be in 10 years it will really rival more modern competitors in terms of performance.
Having said all this, emacs universality and extensibility keep me with it.