https://battlepenguin.com/tech/voat-what-went-wrong/
Deplatforming was a big part of that. Deplatforming didn't stop Milo. His base dropped him because he started defending hebeaphiles & pedophile / men being attracted to teens/pre-teens/boys (there's actually something sadder here; with Milo not realizing he was himself abused ... there's an entire tragic story lost there people don't seem to understand or pick up on because they're too busy hating him).
They might leave the platforms you like, but they move over to Voat, Gab or startup their own Pleroma/Mastodon instances (that get banned from everywhere). Deplatforming doesn't really work in the way you thin it does. It literally gives people more drive to stand up for and behind what Capital-T "truth" they think got themselves banned.