"Decentralized" is the key here. One option, already mentioned, is federation like Fediverse. Even more interesting would be friend-of-a-friend system, where ra

"Decentralized" is the key here. One option, already mentioned, is federation like Fediverse. Even more interesting would be friend-of-a-friend system, where rating of each post is subjective, and weight of someone's upvote is inversely proportional to degree of separation between you and them.