World visit was introduced when the queues were less busy. Some worlds were constantly busy some other (newer) ones on the same data centre were not. That is what it allowed - people to spread the load if they wanted to by visiting another world to quest.

However, when all worlds are full there is no advantage to the world visit as it cannot spread the load due to all worlds being overloaded. It's not broken - it's working as designed but what SE needs is to take delivery of the new servers and press ahead with the the plans they announced so long ago but have been delayed due to well known circumstances which we really do not need to go over yet again.