As long as your new instance is federated with lemmy.world, you can access all of their content. Additionally, there are a lot of instances lemmy.world is not federated with for various reasons whose content you will be able to access as well from a different instance
As long as your new instance is federated with lemmy.world, you can access all of their content. Additionally, there are a lot of instances lemmy.world is not federated with for various reasons whose content you will be able to access as well from a different instance