If we all just defederate with them upon arrival, it seems it stunts their ability to do that. Some users will go to their platform, sure - but if we don’t allow them to piggyback off of our content and engagement, effectively segregating their community away from ours, influence will be minimal, in theory.
Obviously some users will go to their platform, but really, that’s fine. We don’t need to interact with the entire internet.
Sounds good, but only in theory.
I think you almost comically underestimate Metas power to bring eyeballs and therefor content to a platform. In due time the vast majority of Activity Pub „stuff“ will happen under Metas regime. The initial services such as Mastodon or Lemmy will merely be a blip on the radar. Sure, they will continue to exist, but the mass adoption and the network effects that come with it will be under Metas claim on the fediverse. And then it’s „embrace, extend, extinguish“ again (https://en.wikipedia.org/wiki/Embrace,_extend,_and_extinguish).
If a majority of instances defederate from them at the start, meta won’t have the ability to Embrace, Extend, Extinguish in a meaningful way because meta wasn’t embraced back in the first place.
According to Fediverse Observer the fediverse currently has 1.8 million monthly active users (src). Instagram in the meantime has 1.44 billion monthly active users (src).
Lets be generous and use the 12 million total user accounts for the fediverse, not the IMHO more relevant active users. Lets then be very conservative and say that only 1% of all Instagram users will try the new Activity Pub based service Threads. By this estimate the Meta-share of the fediverse will bigger then the whole accumulated userbase so far with 14.4 million users. I think that the 1% is quite conservative, given the marketing might that Meta has.
This means that from the start there will be a “second” fediverse - even if completely defederated from the existing one - with people sharing links, writing comments & thoughts and posting pictures. So there is a potential question to be asked - who is defederating from whom here content-wise?
Secondly I think EEE can also aim at “just” the featureset and technicalities. Safe to assume that Meta has more paid engineers and designers on staff then lets say Lemmy (or Mastodon). Those teams will implement features that the users want, that make their life more convenient. Features that take the currently existing “nerdy overhead” out of the fediverse. All the OS services in the fediverse are then under pressure to either adopt or die.
So yeah, capitalism does what capitalism does, making things marketable. Written wearing my Che shirt.