Do you mean downloading using unsupported 3rd party tools? Because those have to be regularly updated to ensure they even work and could some day stop working entirely if Google decided to care about blocking such tools.
In comparison, GitHub offers a simple clone button (among ways) which gives you everything.
And the point of that argument is that youtube-dl only works because Google doesn't care, and the need to patch it regularly is only caused by the incidental changes in the service. When Google starts caring for some reason, it'll be a difficult battle.
it could be easy to rip, but exact word "rip" is indicating that you are going against service provider's SLA. Meanwhile GitHub is providing tools (git) to get, share content which fits in their SLA.
It would be easy to create a giant mirror of GitHub, for example (once you have a distributed storage system).
Also, GitHub doesn't control what users are viewing (unlike YouTube and Facebook), which makes the platform less of a threat to internet freedom.