There are a lot of downsides to self-hosting your git as well. Especially if you need to deal with high availability, scalability beyond a single server, and/or being open to the public Internet.
I'm not saying you should never self-host your git server, but it's not for everyone.
Good thing Github suck at availability and scalability much more than your friendly local sysadmin...
These days even without trying I get more nine than GitHub.
Arguments against self hosting have to change as our SaaS overlords are decaying in front of our very eyes.
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