The way I look at it, it's best to use *open first* - so perhaps your own Gitlab instance (it's easy to run), or use Gitlab's service if you prefer (although I'd avoid the proprietary features), and then *git mirror* your code in Github if you want the benefit of their network effect. A couple organisations I'm involved in are currently moving in that direction. I've already done it with my personal FOSS projects.
I must admit, in the Debian/Ubuntu/Mint (deb) universe, I'm surprised how seldom it happens. Usually, there're only a couple apps I need to install outside of the default repos, and for all but one or two, they're PPAs...
The way I look at it, it's best to use *open first* - so perhaps your own Gitlab instance (it's easy to run), or use Gitlab's service if you prefer (although I'd avoid the proprietary features), and then *git mirror* your code in Github if you want the benefit of their network effect. A couple organisations I'm involved in are currently moving in that direction. I've already done it with my personal FOSS projects.