Your argument in relation to GitHub does not take in the reality of the effort involved with migrating to a different platform, effort that is likely unpaid, has no logistical upside and stalls the development efforts of a project,

forgejo can automatically import issues, PRs, Wiki articles, and automatic pull/push mirrors can be set up to keep the repo up to date at other places.

the CI/CD system is almost the same.

all the usual features are the same or very similar, including the whole user interface.

not to mention breaking every single source code repository link across the wider internet, links that represent publicity and community engagement.

who said they need to delete the repo from github?

I think it's admirable that a project is asking its community if it should stay or move

it indeed would be admirable if the communication did not contain offensive tones at multiple places.

and also don't forget that they already migrated once. but in the meantime it seems they have gone back to github for reasons unknown to me.