Future instance owners and moderators don’t want users and communities to be able to migrate seamlessly. Mastodon has the same fatal flaw

This is misrepresentative for a few ways.

For one, you can in fact migrate your mastadon account, fairly easily in fact.

For another thing, instance owners and moderators don’t really get to choose whether migration is possible, the code contributors do. I suppose instance owners could start forking their own version of lemmy to make that harder, but ultimately there will always be folks willing to host the “best” version, and so people will just leave