With Meta beginning to test federation, there's a lot of discussion as to whether we should preemptively defederate with Threads. I made a post about the question, and it seems that opinions differ a lot among people on Kbin. There were a lot of arguments for and against regarding ads, privacy, and content quality, but I don't think those are the main issues. Imo, Threads presents a serious danger to the long-term viability of the fediverse if we become dependent on it for content, and our best bet at avoiding that is defederation.

Let's start with these three statements, which should hopefully seem pretty reasonable:

1. It's dangerous for one entity to dominate the activity pool. If, say, one person's instance contributes 95% of the content, then the rest of the fediverse becomes dependent on that instance. Should that instance defederate, everyone else will have to either live with 1/20 of the content or move to that instance, and good luck getting the fediverse to grow after that. By making everyone dependent on their instance for content, that one person gains the power to kill the fediverse by defederating.
2. Profit-driven media should not be the primary way people interact with the fediverse. Open source, non-corporate instances should be able to grow, and that growth will be stunted if most people who want to interact with the fediverse are deciding to go to corporate, profit-driven instances. Furthermore, lots of people went to the fediverse to avoid the influence of these large corporations on social media, and it should still uphold this purpose.
3. People should enter the fediverse with an idea of its purpose. If someone's on the fediverse, they should be aware of that fact and aware of the fediverse's goal of decentralized media. People should think of the fediverse as every instance contributing to a decentralized pool of content, not other instances tapping in to their instance as the main pool.

Now, let's apply these to federating with Threads:

1. This point alone is more than enough reason to defederate from Threads. Threads has millions more active users than all of the fediverse combined, and it's in much better of a position to grow its userbase due to its integration with Instagram. If we federate with Threads, it will dominate content. And that's not mentioning all of the company accounts on Threads that people have expressed an interest in following. While all of this new activity may seem like a good thing, it puts everyone in a position of dependence on Threads. People are going to get used to the massive increase in content from Threads, and if it ever defederates, tons of people on other instances are going to leave with it. Essentially, Zuckerberg will eventually be able to kill the fediverse's growth prospects when he wishes and nab a bunch of users in the process, both of which he has incentive to do.
2. If we federate with Threads, Threads is undoubtedly going to seem like the easiest way to access our pool of content (at least on the microblog side of things). Newcomers already get intimidated by having to choose a Mastodon instance; give them access via essentially just logging into their Instagram account, and they'll take that over the non-corporate alternatives. Federation with Threads means that most of the people who want to see the content we make are going to go to Threads, meaning platforms like Mastodon & Kbin will be less able to grow.
3. When people go to Mastodon, Kbin, Lemmy, Firefish, Misskey, etc., they do so knowing they're going to the fediverse. When people go to Threads, most do so because they have an Instagram account. I'd bet that when Threads gets federation up and running, most people on Threads won't have a clue that they're on the fediverse. Those who do know will probably think of it as all of these small, niche platforms that are kinda offshoots of Threads. That's not the mentality that should pervade the fediverse.

I think that all of this is makes defederating from Threads a no-brainer. If we don't, we'll depend on Meta for activity, platforms that aren't Threads won't grow, and the fediverse will be primarily composed of people who don't have even a vague idea of the purpose behind it. I want more activity as much as the next guy, but that activity being beholden to the corporations most of us want to avoid seems like the worst-case scenario.

"But why not defederate later?"

If we don't defederate now, I don't think we're ever going to defederate. Once the fediverse becomes dependent on Threads for most of its content, there's no going back. If anything, it'd get worse as Threads outpaces the rest of the fediverse in growth and thus makes up a larger and larger share of activity. Look at how desperate everyone is for activity — even if it means the fediverse being carried by Meta — right now, when we're not used to it. Trying to get instances to defederate later will be nigh impossible.

"Why not just block Threads yourself?"

Even if that were a feature, it completely ignores the problem. I don't dislike the people on Threads, and I don't think their content will necessarily be horrendous. The threat is people on non-corporate fediverse platforms becoming dependent on Daddy Zuck for content, and that's something that can only be fought with defederation.

To close, imagine if Steve Huffman said that Reddit was going to implement ActivityPub and federate with Lemmy & Kbin. Would you want the fediverse to be dependent on Reddit for activity? Would you trust Huffman, who has all the incentive in the world to pull the plug on federation once everyone on Lemmy & Kbin is hooked to Reddit content? This is the situation we're in, just with a different untrustworthy corporation. The fediverse should not be at the mercy of Threads, Reddit, The Site Formerly Known as Twitter, or any other corporate platform. It's better to grow slowly but surely than to put what we have in the hands of these people.