ZFS is a great filesystem, with many, many features. But for all that it is still easy to manage, in my opinion easier than other filesystems. Managing storage is usually a high risk task, which makes automation harder. Would you change the size for a critical filesystem with an automated method? If it is an ext3 filesystem on LVM and software-raid, maybe not. If it is on ZFS, a low risk modification of the quota could be enough, e.g. zfs set quota=800g rpool/criticalfilesystem. That’s easy to automate. Nowadays automation becomes even necessary because, the amount of ZFS filesystems is growing. And if you like to use more features you likely need to set more ZFS properties.