Two hours ago, they were down constantly, but now they seem to be up. Github seems to be getting increasingly reliable!
You can always pick an appropriate window of time, point to it, and say "See, there's a trend!". That doesn't make it so.
Github used to go down much more often than they do now - calling them 'increasing unreliable' really just shows that you have begun depending on it more heavily.
Their status page [1] still indicates a 99.85% uptime in the past month, and before this and yesterday's problem, their status page was mostly green across the board for a couple of weeks. It depends on your requirements, really. Nobody can guarantee 100% uptime.
'Sufficiently' is meaningless without a qualifier. Sufficiently for what purpose?
There is a value proposition involved - you can run your own source code hosting and anything else, but it costs money and time to do it. Especially if you need six nines of uptime.
You can always pick an appropriate window of time, point to it, and say "See, there's a trend!". That doesn't make it so.
Github used to go down much more often than they do now - calling them 'increasing unreliable' really just shows that you have begun depending on it more heavily.