A quick search still proves you wrong in regards to Twitter.
https://twitter.com/search?q=%23StolenElection&src=typed_query
https://twitter.com/search?q=%23AllLivesMatter&lang=en
As for Facebook...
I can't say I have been banned on Facebook and I'm not on Twitter. The former I've only use to keep in touch with friends, family, classmates, and co-workers. But I have engaged in political discussions and have had may stuff marked or my comments removed when I posted on a public page. I cannot remember the circumstance but it was a joke over racial discrimination. Supposedly the person's last name was White and I made an... off-color remark. :D And it got flagged. I don't think she was the one who flagged it, either.
But again, from what I understand; the people who Twitter removed was the QAnon group and Donald Trump. Honestly, that's no real loss. Any more than if someone removed Keith Olbermann or PETA from Twitter.
And no one was permanently banned, from what I understand, except a select few repeat individuals who had been banned before. The exception being Trump who then broke Twitter's TOS by trying to circumnavigate his ban. Pretty basic stuff when you are banned from any kind of forum or platform, honestly.