Well yes and no. There's no existing network (for something new), so certainly there's no network effect making them grow.
On the other hand the pitch to get people to join is weak. I don't pitch it to my friends because (currently) its a pretty poor experience compared to what they are already using.
I don't think the fediverse experience is poor, I rate it as superior to the walled gardens.
I don't pitch it to my friends because quantity invariably destroy quality, or at the very lease hide it behind a huge pile of dirt. I don't pitch it because people who are interested in a better internet already care and know how to find it. I don't want to ruin a nice well behaving network.
On the other hand the pitch to get people to join is weak. I don't pitch it to my friends because (currently) its a pretty poor experience compared to what they are already using.