I mean, if someone said, "I've successfully ported Vim to Android!", my first thought would be, "Why in god's name would I want to run vim on my phone?"*
* Ruling out, of course, someone plugging their phone into external KVM.
And beyond that, platforms have affordances which you should want to leverage. A smartphone has a very direct and tactile interaction model, but my computer pairs an extremely precise pointing mechanism with a good way to input oodles of text and chord shortcuts.