How do you know? Their voices might just be someplace where you (and people you know) don't hear them. The world of discourse is wider than our awareness.
If Alex moves to another platform wouldn't part of his following move to this platform? Wouldn't that grow others in that new platform.
Isn't deplatforming just replatforming. With every deplatform doesn't it leak more users to the new platform.
If they deplatform them one day it could be you.
Please don't put words in my mouth. I said I did not need "perfect evidence." I cited evidence, albeit imperfect. Whether it's strong enough to change someone's beliefs is between them and their epistemology. That's all I have to say on this subject.
But you need one to change hearts and minds.