In my case, it’s 2 computers primarily setup this way. My desktop and my tabtop (Lenovo Yoga laptop). I use snapshot subvolumes for things like / and /home, though my only real snapshots I utilize live on / specifically. I did go a little overboard because packaging I’d intended for things to be managed normally my snapshots, but some things package things to /opt, which is wasn’t really supposed to be for. Yet people are packaging with that intention.
Anyway, I’ve moved my /opt, /usr/local, and /boot into / as of now, in this process, but I see value in keeping things like /srv, /root, /var/cache, /var/lib/crash, /var/lib/containers, /var/lib/libvirt/images, /var/log, /var/spool, because they are not parts of the system that would ever need to be included in a snapshot, specifically. I even designed my bash-customization script for use with EndeavourOS to always set it up this way.
What’s more complex is trying to add in LUKS to this, or even simplified setup, at all. Right now, the only way I can see this semi-sorta working is quite literally by not using LUKS, and that’s annoying.