Roblox, kids, and online gaming

My son is 8 and is obsessed with Roblox, Minecraft, and Fortnite. He loves that he can play these games online with his friends and other kids. But I just found out that he has an entire online friends list of people he doesn’t even know. I tried explaining to him about online predators but he claims he does t talk to

Them. I told him he should unfriend everyone he does not know and he said that will make the game boring. What are you thoughts on this? Anyone else experience this stuff first hand? What kind of rules do you set for your children?