Because Vim is not an editor. It's an idea. Probably one of the best ideas that ever happened in the computer science. Another great idea (often mistakenly called a programming language) is idea of Lisp. When you combine these ideas together you can get something insanely powerful. If you never tried Spacemacs or DoomEmacs, I encourage you to check them out.
Emacs: put all applications into emacs! Vim: make other applications controlled like vim!
I'm a vim user and I prefer #2.