As for Linux from Scratch - This is something that's been on my radar, but without the part I'm truly interested in (learning more about SysV) then I'm less inclined to bother. I don't buy the reason of Gnome/KDE - isn't LfS all about the basics of the distro than building a fully fledged system? If it's the foundation for the other courses, but it still feels weak that it's so guided by a future GUI requirement for systemd when it's talking about building web servers and the like in a 500Mb or less as the motivation.
Freedesktop wants to kill X11 and are working continuously on that, to the point if rejecting patches and banning developers.
Popular desktop environments are increasingly depending on Linux-only things. KDE has officially removed support for FreeBSD in Plasma login manager (because of logind dependency).
Gnome 50 plans to obsolete X11 completely.
If you want that simple, bright future of yours, you’ll have to fight/work for it.