It’s not about collecting data, the fediverse freely shares all its data by nature.

Threads has a lot more users and Meta would use that to attack smaller instances, a bit like what Lemmy world was doing a few months ago.

The biggest instances usually have the most communities and if they ban other instances, rival members are more likely to migrate over than to create copy cat communities.

It’s not terrible at the moment but bringing in threads is like throwing a shark in a shrimp tank.