This is one of the strengths of a federated system run by people who aren't looking to profit. Firstly, they care about their users and are more likely to take difficult decisions, like the one Ash has made, for the good of themselves and their users. In doing so everyone involved has time to make an orderly move. Secondly, the service survives. Mastodon didn't shut down. The Fediverse didn't close. One beloved insta…
And who will pay for that openness and decentralization? Let’s hypothetically say that Twitter is closed, millions of users discover Mastodon and move. Mastodon instances will be down in matter of seconds. How do you approach this? By volunteers adding more instances(that they can close anytime)? This will not change anything. Everything cost money and living in an “free” world bubble isn’t helping in any project ado…
This isn't a law of the universe, it's just software people haven't written yet. Installing new client-side apps was hard, until it wasn't. "Anyone can start their own instance" will be easy once someone writes the software to make it so. (Presumably a cloud provider like AWS, since that's who stands to profit from lots of people wanting to run server-side apps)