> this is possible via snapper on Linux + btrfs but needs complex installation and is not so integrated

FWIW, openSUSE defaults to btrfs on the root filesystem and uses snapper in a very similar manner to zfs boot environments on FreeBSD. I don't have a lot of experience with the latter, but I have been running openSUSE Tumbleweed on my desktop and primary laptop for about 10 years now, and the btrfs+snapper arrangement has worked pretty well for me.

(I also run FreeBSD on my home server and just did the upgrade to 15.0 this weekend, which left me wondering why I had procrastinated this upgrade for so long. It went perfectly fine.)

> FWIW, openSUSE defaults to btrfs on the root filesystem and uses snapper in a very similar manner to zfs boot environments on FreeBSD.

CachyOS (Archlinux derivative) with either GRUB (since recently), or Limine Bootloader(since longer), too.

Are you using pkgbase on 15 now or still using the old approach ?