I see people repeatedly misunderstand this aspect unfortunately, because it's hurting the adoption. It has no effect what instance you are on, you are all on Activity Pub. You can join any instance you want and it will be no different from joining any other instance. You can interact with anyone on any instance. This is just like how you only need to know my Email address to send me a message, you do not need to also use the same Email provider as me.
As you can see, the bigger server 50% more posts, 40% more participants, 25% more posts today.
As you surf your "local server", you don't get "everything" from the Fediverse. If you care about that, you likely want to join the "biggest" server you can.
Personally I don't care too much about this. There's more content added to the Fediverse than I have time to consume, and so seeing a slice based on who I currently follow and the server I utilize is plenty for me.
But it also makes sense if it bothers people who don't want to miss out on some zeitgeist.
There are incredibly important differences in user experience when picking one instance over the other.
A very small one has a large likelihood to disappear. Each instance has different moderation rules. On a small instance, you don't even see entire threads and lots of other stuff does not sync properly.
