It looks like the technology behind this forum is not well-understood by you.

If you create an account on http://piefed.zip , you will see practically all of Fediverse, basically regardless of defederations. You have to go the settings there and specifically click some buttons to unblock a group of instances most people don't want to see. But it can be done and you'll get what you're looking for.

I think you’re misunderstanding how .world works. Lemmy.world doesn’t mean it’s open to everything, that’s just the instance name. They actually block and defederate from a lot of communities and instances.

If you want to see everything and judge for yourself, just pick an instance with a minimal defederation policy. That’s why I picked .zip so I can curate my feed the way I want it.

Before signing up for an instance, scroll down and read their instance policies so you understand what you’re signing up for.

If you want to see everything, world might not be the best place. If you click on blocked there, you see all the instances that are blocked by lemmy.world.

There are instances that don't, or barely, block any instances. That's where you are most likely to find "everything"