Once you learn to jump quickly between words, lines, etc. and change whole blocks of text with a few strokes you discover another dimension of vim that's very hard to replace with other tools.
C-a and C-e and a dozen of others are there, yes, but good luck if you think you can use M-%, M-h or whatever is the Emacs equivalent of Vim's text-objects and motions (which is what the parent was thinking about).