I get wanting to phase out Mercurial in favour of git. But why did they have to choose Github T_T

Ideally they would have just hosted a their own Forgejo instance (heck, a Gitlab one would have been better too FFS). Even just using Codeberg and donating would have been better

The for-profit side of Mozilla seems to have succeeded in purging most of the principles Mozilla used to have (IK they have been eroding over the years and sometimes been too "pragmatic", this is just the cherry on top of a long series of shitpiles)

if Mozilla actually stood for a free/libre future they'd push Forgejo to the lvl they need it to be (if it already isn't capable of all that stuff. Haven't rly interacted much with it).
Since they will still keep the CI/CD on Mercurial for now, there is even less valid reasons for using Github...