Feel free to vote for this Feature Request if you feel it should be default in TN or at least a UI option.
I have a feeling this issue won’t impact smaller environments as much as having a set of permissions per dataset/share will be sufficient and if you need a different set of permissions you will most likely just create an new dataset and share. However in larger more complex environments it’s too unwieldy to create a dataset and share every time you need a new permission group as you would end up with hundreds if not thousands of datasets (and intern even more snapshots) and I can tell you from experience that doesn’t end well.