Given that constraint, I picked up Vim and have used it for the past 6 years. Tried Emacs at first, but it didn’t play well on Windows (not sure if user error!)
So I definitely encourage “reinventing the wheel” on multiple platforms, as long as the platform is popular enough. Competition doesn’t hurt.
The thing that would get me to use Emacs is a plugin implementing Neovim's remote editing protocol. Vim is an incredibly deep state machine, and no plugins that reimplement it get things exactly right.
If you love modal editing, as I do, you can use EVIL mode to emulate Vim quite well. I used Vim for years and switched within a month, most of the transition was in getting used to all the tools built into Emacs. Movement was identical, even things like text objects and Vim-surround work well.
The quality of Emacs packages are very high and almost always “just work”. And when you do have to read the documentation it’s very easy to find and understand.
Sublime Text has a plugin which implements the API; it runs full blown vim plugins.
.. .. I didn't realize the integration was that far along. I'll have to give Sublime another look.