> Emacs brings nothing new to the table with respect to editing model, it's essentially notepad

Emacs (1976) predates Notepad (1983).

I do understand what you mean, though. For people using Windows, Emacs needs to be sought out and installed, this effort needs to be justified (assuming one is permitted to install software at all), and hence the requirement for Emacs to "bring something new to the table" over the default option, Notepad, which is just /already there/.

The most basic, implicit, requirement, then, is exactly as GP says: availability. All else follows.