Youtube is being an ass about guns specifically. They had vague rules about assembly instructions including not being allowed to show someone screwing in a suppressor. Then they did the typical google thing and offerred no discussion or recourse options for talking about the rules to any of the youtubers. Essentially, fuck you, you do what you're told type of deal. It was enough that all the gun youtubers had legitimate worries about their job security in the short and longterm future. They've since walked back that specific rule, but there are still a lot of other rules restricting what kind of gun related content is actually allowed. And all the channel owners know that google can and will cut their gun content on a whim without forewarning or talking about it.

You also see this with their rules about swearing in videos. Whatever makes the advertisors happiest apparently.

I have no idea. I learned this from the not political gun youtubers and various other hobby interest channels telling me they had a floatplane account set up.