Isn't this what backups are for?

Your operating system might. But it doesn't protect against your machine dying. That's a different problem with different solutions. You could self host on a different machine...

Is github the most accessible? It is the most popular and best for discovery but a discussion around if gitlabs or bitbucket being more accessible could be had.

I was thinking: what about just some different PC where you got ssh access. Yes this might not be accessible enough. So the next thing could be gitlab. They offer free private repos