If the moderation of a certain instance is not good, other instances can block it.

See the awesome lemmy github repo.

If someone has some unpopular opinion you can still see some people upvoted it and therefore appreciated it (so you can decide to read it).

Anyone can self-host the software on their own server. Users can join an instance they like.

You can view and comment on other servers (instances) as long as the instance you are on hasn't blocked the other instance.