I mean it's a separate project so it has nothing to break "compatibility" with and it's made clear [1][2] the aim is to be different. Given the author is part of the suckless community I really don't think they care about attracting users either.

I admire Vis but at the end of the day a text editor is just a tool. When the investment into changing out such a tool becomes worth it is entirely user dependent.

[1] https://github.com/martanne/vis#non-goals

[2] https://github.com/martanne/vis/wiki/Differences-from-Vi(m)