I just read this point in a comment and wanted to bring it to the spotlight.
Meta has practically unlimited resources. They will make access to the fediverse fast with their top tier servers.
As per my understanding this will make small instances less desirable to the common user. And the effects will be:
Meta can and will unethically defedrate from instances which are a theat to them. Which the majority of the population won't care about, again making the small instances obsolete.
When majority of the content is on the Meta servers they can and will provide fast access to it and unethically slow down access to the content from outside instances. This will be noticeable but cannot be proved, and in the end the common users just won't care. They will use Threads because its faster.
This is just what i could think of, there are many more ways to be evil. Meta has the best engineers in the world who will figure out more discrete and impactful ways to harm the small instances.
Privacy:
I know they can scrape data from the fediverse right now. That's not a problem. The problem comes when they launch their own Android / iOS app and collect data about my search and what kind of Camel milk I like.
My thoughts:
I think building our own userbase is better than federating with an evil corp. with unlimited resources and talent which they will use to destroy the federation just to get a few users.
I hope this post reaches the instance admins. The Cons outweigh the Pros in this case.
We couldn't get the people to use Signal. This is our chance to make a change.
"unethically defedrate"? I think you may have misunderstood how federation works, since "defederate" is just another word for "ban yourself from seeing that instance's content", if Threads defederate from a small Mastodon instance, for example, that Mastodon instance can still see all the content on Threads, but the Threads user won't be able to see anything posted by that Mastodon instance.
Also, any instance can and should be able to federate and defederate any other instance for any or even no reason, that's the entire point.
I think threads being able to make content that's a threat to them invisible to their users by "unethically defederating" is exactly what the op is talking about. What they were likely referring to is this:
https://ploum.net/2023-06-23-how-to-kill-decentralised-networks.html
Doesn't matter that users from other instances can still see threads content. It's about threads accumulating the majority of users due to better infrastructure and then silencing smaller instances they deem a threat to them by defederating. It's only been a few hours and they've crossed 30 million users.