I feel like the way activitypub works lends itself to people forgetting that each instance is technically its own entire "Reddit", with their own admin team, who will of course have their own views, biases, and moderation policies.

Some will be completely over moderated, some won't have any moderation at all. Some will be full of tankies, some might be hard right.

The difference between here and Reddit is that you have to actively filter unwanted stuff out - there's no algorithm doing it for you. Perhaps that's what some people find unpleasant about here?