Metcalfe's law says the value of a communications medium goes up with the square of the number of participants.
If the total number of people interested in federated social networks is N, a single pool of people using compatible protocols -- AP, right now -- generates ~N^2 value.
If you split that in 2 even groups, the value of each group is ~N^2/4, and total value is N^2/2.
Every time we split the fediverse, we drive down value significantly.
So, if you care about federation, don't split.