As a long time BSD and UNIX user, I disagree with the premise that containers have only recently been usable. Even on Linux, solutions like Proxmox made contain

As a long time BSD and UNIX user, I disagree with the premise that containers have only recently been usable. Even on Linux, solutions like Proxmox made containers incredibly useful in the pre-LXC / pre-Docker days. And that’s discounting FreeBSD jails, Solaris Zones, etc which have existed a lot longer. If anything, Docker just made containers trendy (they gave more talks at more conversations, etc) when before it was seen as a niche toy compared to virtualisation which few had heard of and fewer had bothered to look into. However being trendy doesn’t mean better nor easier to use.