I wouldn't say that, considering we (feddit.org) are currently experiencing a large growth from reddit users and others going away from US based platforms.
Assuming that the growth on both sides is identical, it would mean that once you put the flat Earth on its side it would be balanced, as all things should be.
That question is for you to answer, but in my opinion it's not worth it throwing away a long friendship over politics. You are allowed to have disagreements. Additionally if all his non-politically right friends / associates throw him away if might only push him even further into right politics.
This is what happens, when global warming lights the turtle on fire.