Or it is about the friends you loose after you have successfully installed Gentoo and now maintaining it.
Fun aside: I used Gentoo for more than a decade (15 years?, idk). Since I am back on Debian stable, I don’t feel like I am missing out on stuff I want to try, because I don’t have to wait or solve useflag issues anymore. I still think, Gentoo is a solid distro, but I have other hobbies, too. If it were my sole job to maintain a Gentoo system I would do it. But I don’t want to deal with it anymore in my spare time.
Interesting. Why not use systemd-nspawn? From what I understand, the kernel is shared anyway.