Linking communitirs !iso8601!@someinstance is one of the core reasons why Lemmy failed to capture even 1% of 1% of 1% of Reddit’s userbase at probably the greatest time of turmoil of discontent with that site for the next 5 years.
This formulation insist on centralizing communities in single instances and creates both fragmentation of the community while also making them concentrated on whatever the biggest one is.
The few users that make it past the registration catastrophe, when they realize this is how communities work, they just leave, because it means Lemmy isn’t federated where it counts. Communities end up owned by a single instance owner and mod team. It’s Reddit except somehow worse.