I don't follow ... patches via HTTP is a repository, patches via email is not?!
But apart from sending changes via email (which is actually a very good way to go for small(ish) changes--actually, it is so good, the Linux kernel developers use exactly that: git can generate emails that are both human-readable, so you can easily review and comment on patches, but also can be imported automatically into a repository by the recipient), you can just send pull requests via email? You simply put into an email the URI of your git repository, wherever it is hosted, and the recipient can pull from it. That is the power of an open distributed system like the internet.
And to spin this a bit further: Actual "hosting" isn't even necessary technically. Especially once we get rid of IPv4 and NAT, it should be trivial to spin up a git server instance on your workstation (or maybe your smartphone, as that probably is online 24/7) so people can pull from there. Whether that is practical? It well might be--but my point is more to show what is technically possible.
And yes, all of that was possible with a "previously popular solution"--git existed before github, obviously, and its popularity is what caused github. Also, all of that applies just the same for other distributed SCMs, of course.
But apart from sending changes via email (which is actually a very good way to go for small(ish) changes--actually, it is so good, the Linux kernel developers use exactly that: git can generate emails that are both human-readable, so you can easily review and comment on patches, but also can be imported automatically into a repository by the recipient), you can just send pull requests via email? You simply put into an email the URI of your git repository, wherever it is hosted, and the recipient can pull from it. That is the power of an open distributed system like the internet.
And to spin this a bit further: Actual "hosting" isn't even necessary technically. Especially once we get rid of IPv4 and NAT, it should be trivial to spin up a git server instance on your workstation (or maybe your smartphone, as that probably is online 24/7) so people can pull from there. Whether that is practical? It well might be--but my point is more to show what is technically possible.
And yes, all of that was possible with a "previously popular solution"--git existed before github, obviously, and its popularity is what caused github. Also, all of that applies just the same for other distributed SCMs, of course.