I think it's due to multiple reasons, and the threshold of rejecting the course of GitHub/Microsoft/the USA seems to have reached a level where GitHub stopped being the "default" place to be for a number of projects already.

And if you are at a point were you need a Codeberg account anyway already, why not move your own projects there (or use it for new ones)?

Not to mention, the Forgejo project is at a stage were it feels like your bug report/feature request/contribution has an actual impact.