I have been using it for a few months, and it is working well. By default, you get daily snapshots, with a retention of 7 days; I believe you can buy more.
rsync.net is no-frills remote storage that gets out of the way of whatever you want to do. In my case, this is rsync over ssh, but they also support borg.
I am clearly not hip to popular culture.
They are, however, aces at reiterating the problem.