Earlier quoted context omitted.
It's not entirely clear to me whether you're talking about using GitHub for your own production tooling, or as a source for some arbitraty third party component. If it's the latter, then I completely agree with you. Use a read-through proxying package repository. I don't care if you run it yourself or if you pay a provider, but don't pull stuff from the origin every time you build. In the general case, adoping an ext…
Yeah, I was talking about access to third-party dependencies, which I had assumed was the crisis the OP had in mind. I've since read many sibling replies fret over build automation or source code storage, but some downtime in build automation will rarely damage customers and (my goodness) I hope people aren't trusting the only copy of all their IP to a business partner and that they always have a very recent backup s…
There's still a question of how strong an ownership we need -- for example, my mail server is owned by OVH, and its backups are sent to rsync.net. I consider that to be sufficent ownership of backups. I'm much more likely to lose my files than they are.
I'm sure that GitHub also have backups, but they're not for the benefit of their customers.