Part of my point was that it's difficult to get into (still worth it overall), but another part is definitely that technology has moved on, and emacs often reminds me of its age there.

No matter what, emacs still feels "alien" in my OS's desktop interface with its UI concept, and never fully integrates. That's fine if you don't want it to integrate, but I actually like some concepts of my OS's UI a lot, and miss them in emacs.

And elisp is not a very good language, born of a time where programming languages still had a long way to go (at least in the mainstream, academically it always seems a bit different to me). They are actively trying to fix things, e.g. the adoption of lexical binding, but the scope of this effort also shows how emacs is a very big ship that is hard to change course.

Someone else mentioned lack of proper multi-threading in another comment now, and this is also very noticeable.