I always assumed it was more or less targeting the federation of issues/MRs.
The git side of things is already distributed as you said, but if you decide to host your random project on your own GitLab instance you’ll miss out on people submitting issues/MRs because they won’t want to sign up for an account on your random instance (or sign in with another IdP).
This is where a lot of the reliance of GitHub comes from, in my opinion.
Oh interesting, it’s been a while since I have tried to use Apple TV (roughly 7 years or so - I don’t use any Apple devices anymore), this wasn’t available at the time so I’m glad to see there’s finally some native support.