The problem with federation with Meta is that it encourages Meta to develop and contribute to the infrastructure. Which sounds great, but the record is poor on that front.

Once a company with huge money starts working on your infrastructure, they're going to make changes, changes that maybe the community doesn't agree with, but since all the money is being funneled through one of two companies, they make the decision.

Then the company decides that they don't want to keep supporting something that doesn't make them any money. Since Meta would theoretically bring millions of users from their platforms, they could decide to suddenly cut out all non-Meta instances. Now we're the odd ones out, your friends are wondering why they can't reach you anymore, you're suddenly offline.

Embrace, extend, extinguish. It happened with XAMPP, it happened with Java, CSS, most browsers are Chrome based, 'exchange' email servers, etc.

The best thing to maintain software freedom is to never open the door to huge companies.