You miss-represent the fediverse. Users aren't locked in. If someone buys one instance and you don't like it, you move.
Maybe you will but people in their majority won't do that. It's too much operations. Also they might not even be aware of the transfer. Plus if an instance offers good services there might be a technological price to pay for leaving, like leaving instagram. All instances are not equal, specially if there are more interfaces in preparation.
The emails revealed that Zuckerberg wanted to buy Instagram as it was becoming a threat to Facebook.
"Facebook, by its own admission saw Instagram as a threat that could potentially siphon business away from Facebook," Nadler said during the hearing on Wednesday.
"So rather than compete with it, Facebook bought it. This is exactly the type of anti-competitive acquisition the antitrust laws were designed to prevent," Nadler added.
Facebook bought Instagram for $1 billion in 2012, a shocking sum at that time for a company with 13 employees,
Facebook bought the adoption, they bought the users.
So what will you do about an instance called "rofl.lol", which is huge, which has a lot of fans locally who want to keep interacting with it and which also allows spammers? Will you keep federating or will you defederate it?
If you don't defederate this will become and endless whack-a-mole of bans with a drop of quality.
Do you have any source for this marketplace of instances?
We have a bigger problem and it's popularity. Some instances will want to become as big as possible, for resell value.
So they will be encouraged to let the maximum of people registering a new account, including bots and spammers. Because they make the numbers and they start the snowball effect.
Didn't you all looked a the most populated instances/magazine when you registered magz, and you didn't care about the mags with zero activity? Well, you are encouraging the process in a way.
People will be reluctant to defederate or to ban popular magazines from other subs. So the float of spammers is unlikely to stop, because the person who makes the decision, the admin of the instance, will welcome them. And you won't ban the instance or the mag.
edit: to whomever is interested in privacy, the downvote is from a troll, mass downvoter called @DarkThoughts. The link is good and the source as well.
I don't see a world where this works, the numbers just don't add up. Anyway meta will never allow you access if you don't sign a ToS with them. No ToS, no service, the lawyers will see to this.