>the primary evidence that deplatforming works seems to be a study that shows that bigots left Reddit and declares victory, completely ignoring that Voat started at the same time.

https://www.vice.com/en_us/article/bjbp9d/do-social-media-ba...

Deplatforming leaves people with a smaller audience. Only a fraction of the audience follows a banned person to another platform. Voat is nothing compared to Reddit.