Yes, I've been using it for a few years and made my own plugin with a couple dozen users. Then I discovered Vim overnight and never used Emacs again (literally).
> But claiming that it doesn't bring anything new compared to Notepad is really strange
It does indeed sound strange because you missed the "with respect to editing model" which is crucial for my point. Emacs has nothing in it other than Notepad + a large number of ad-hoc, non-coposable plugins each doing one task.
> Things like rectangular cut and paste, vertically aligning stuff
Ad-hoc things that do only one very specific task each. Incomparable to Kakoune's powerful and composable way of interacting with text.
> infinite undo, undo restricted to the selection (region)
Orthogonal to the editing model. These can be slapped on top of any text editor, be it vim or notepad. Just make a plugin.
Wow, and here I thought I had seen all derogatives about Emacs ;-) But claiming that it doesn't bring anything new compared to Notepad is really strange.
1. Emacs predates Notepad by one or two decades. 2. Have you actually had a look at what is actually included in Emacs? I am not talking about mail readers and other "apps" inside emacs. I mean just for editing text in a non-mode specific way. Things like rectangular cut and paste, vertically aligning stuff, infinite undo, undo restricted to the selection (region) and many many more stuff. That Notepad doesn't have.