That “burden of migration” you're rightly complaining about is the exact lock-in effect that the whole #GiveUpGithub discussion is centred around! Migrating issues and PRs isn't a hassle because @Codeberg Announcements is shit, but because GitHub try their very best to add as much friction as necessary to stop you from leaving.

Forgejo (the platform powering Codeberg) is actively working on federation, i.e. the diametric opposite to lock-in.

If you can't bother to use privacy-respecting open-source tools, why do you develop a privacy-respecting open-source app in the first place?