Another consideration is UDP. Games on anywhere but browsers use UDP because it's fast – no round trip necessary, no acknowledge packets, no waiting on missing

Another consideration is UDP. Games on anywhere but browsers use UDP because it's fast – no round trip necessary, no acknowledge packets, no waiting on missing ranges to free up data from the buffer. CRDTs need TCP/IP for the guarantee of getting all of the data without data loss. Only when a CRDT is fully up-to-date can you be sure that the resulting data structure is synchronized. This means UDP wouldn't be ideal for communicating CRDTs