Sharing this blog post because I liked reading it. Nice photos and images and shows lots of options. The section about Gentoo Linux suggests it is unclear whether Gentoo uses Systemd. From what I’ve seen after tinkering with a Gentoo container last week is that Systemd is an option for “make world” but not the default.
I posted this link because I liked what the page showed, but meanwhile I learned from the comments a few things about Systemd and its modular state and decisions that Linux distribution maintainers make. That was very good to hear. Thank you all !