github basically shoves a webby frontend and workflows on top of someone else's work. That's all fine and good but github is not git.
As a professional IT consultant, I want tools, I use lots of other's and I also create my own and I also generally insist on hosting my own. I'm also a fair carpenter and several other trades. I have tools for all my trades and I look after all of them. That way I can guarantee quality - or at least reproducible and documented quality.
I'm sure you are fine with abrogating responsibility for stuff that you are not able to deal with - that's all good: Your choice.
EDIT: Sorry, forgot to say: "Yay cloud"