As a former Magit maintainer myself, I would really hate to see much
effort going into rewriting it instead of improving it :)
+1 on "let's not re-invent the wheel (and re-find the same bugs and fixes and fixes to fix the bug introduced by those fixes)". Let's optimize the developer time in making things better and writing new things.
I agree with the datapoints that followed.
CC-ing Jonas for a more current perspective.
If Jonas is on-board with making Magit an official part of Emacs, then half the problem is solved :)