@Deus
True.. it's a network effect. You need a large number of people with whom you interact on your current platform to move onto #fediverse, otherwise it makes little sense.
One of the reasons for many to #crosspost was to encourage others to move, but cross posting also has the disadvantage that people see you still active on the old place, hence don't bother to move.. it's a vicious cycle.
Same like asking people on whatsapp to use a more privacy focused app like signal or xmpp!