When I use sudo zfs get all, I see that both my old pool (data) and my newly created pool (backup) are on version 5, which I think refers to the zfs version, not the zpool version.

Not a whole lot of exciting stuff since 8.0, but for anyone waiting for it to not be a "dot zero" release, you can now likely leave 7.x or 6.x behind. Some of the new 8.x stuff includes network ...