FreeBSD has - can have - better ZFS support than Linux. Ubuntu comes close, but then you're on Ubuntu...
Several things that Ubuntu misses:
- lack of ZFS Boot Environments - https://is.gd/BECTL - https://is.gd/BEADM
- no bootloader integration
- still requires ancient EXT4 or XFS /boot to start system
... and while the version of ZFS is newer on FreeBSD you can always install these packages and have LATEST OpenZFS available:
- sysutils/openzfs
- sysutils/openzfs-kmod
Hope that helps.