They are politically motivated. For example, I’ve been banned from Twitter for defending Kyle Rittenhouse, who engaged in lawful self defense against a number of violent assailants. Why? Because the left has decided it serves their interests to paint him as a mass murderer (indeed Facebook has an official policy that he is a mass murderer).

Facebook also regularly censors viral pro-trump content and project veritas has exposed this.

I wish it weren’t so, but it is. I’ve experienced it firsthand.

I've seen a lot of retellings of why someone was banned that end up being a bit generous, particularly if experienced first hand.

It's tough to take these at face value because we trust and believe in the things that define our ideology and take any challenge to our presentation of that as an attack on the underlying ideology.

I'm guessing that's because "viral pro Trump content" is very frequently xenophobic& racist content, includes calls to violence and is full of conspiracy theories. If a site doesn't moderate that sort of stuff, it frequently goes to shit, I know inadequate moderation on that front had made reddit much much worse.

Also this sort of stuff can lead to real world violence like when Facebook let violent vigilantes organize on their site it led to Kyle Rittenhouse killing two people.