The reason ZFS isn't the norm is because it historically was difficult to set up. Outside of NAS solutions, it's only since Ubuntu 20.04 it has been supported out of the box on any high profile customer facing OS. The reliability of the early versions was also questionable, with high zsys cpu usage and some times arcane commands needed to rebuild pools. Anecdotally, I've had to support lots of friends with zfs issues, never so with other file systems. The data always comes back, it's just that it needs petting.
Earlier, there used to be lot of fears around the license, with Torvalds advising against its use, both for that reason and for lack of maintainers. Now i believe that has been mostly ironed out and should be less of an issue.
> The reason ZFS isn't the norm is because it historically was difficult to set up. Outside of NAS solutions, it's only since Ubuntu 20.04 it has been supported out of the box on any high profile customer facing OS.
In this one very narrow sense, we are agreed, if we are talking about Linux on root. IMHO it should also have been virtually everywhere else. It should have been in MacOS, etc.
However, I think your particular comment may miss the forest for the trees. Yes, ZFS was difficult to set up for Linux, because Linux people disfavored its use (which you do touch upon later).
People sometimes imagine that purely technical considerations govern the technical choices of remote groups. However, I think when people say "all tech is political" in the cultural-war-ing American politics sense, they may be right, but they are absolutely right in the small ball open source politics sense.
Linux communities were convinced not to include or build ZFS support. Because licensing was a problem. Because btrfs was coming and would be better. Because Linus said ZFS was mostly marketing. So they didn't care to build support. Of course, this was all BS or FUD or NIH, but it was what happened, not that ZFS had new and different recovery tool, or was less reliable in the arbitrary past. It was because the Linux community engaged in its own (successful) FUD campaign against another FOSS project.
Canonical took a team of lawyers to deeply review the license in 2016. It's beyond my legal skills to say if the conclusion made it more or less of an issue, at least the boundaries should now be more clear, for those who understand these matters more.
Earlier, there used to be lot of fears around the license, with Torvalds advising against its use, both for that reason and for lack of maintainers. Now i believe that has been mostly ironed out and should be less of an issue.