People use the most convenient way to collaborate, and that's for me currently Github. Really hope, some day a better alternative with ForgeFed becomes reality.
Open source was M$' archenemy that they knew they couldn't compete against. So they slithered in and co-opted it and everyone just ignores the perils and carries on.
Not to mention the fact that they trained copilot using code on it, without informing or taking permission from the authors and they justify it citing fair use policy.