A bunch of people are trying to use datasets to implement permissions and ACLS via the GUI.
I use a zsh shell via ssh and give normal debian commands and scripts and automations. You cannot automate hardly anything via a gui. That is the #1 reason I abandoned TERRA-MASTER OS.

However, on TrueNAS there is the dataset dilemma.

Willnx says about datasets on truenas:

If it helps, here’s how my box at home is set up (with the datasets and such):
Vol1
+Berkeley (Unix dataset)
–>So many exports…
+Redmond (CIFS dataset)
–>Two different shares for my only two Windows boxes. Unique permissions for each.
+FTP (Unix dataset)
–>For the crap I always have to re-download when I make a new VM/ build a new PC.

I don’t have any quotas set up on these datasets either. I don’t care how big any of them get, provided it doesn’t fill my NAS 100% and turn it into a big brick.
Instead, I set up a reserve space on Vol1.

To me, the real power/ benefit of multiple datasets are:
More granular snapshots (Clones too)
Different compression preferences
More granular Deduplication control

Using datasets (in my option) for permission control is kind of like using a big wrench to hammer a nail; it works fine, but not it’s intended use.

My thoughts:

So, what I am hearing above is snapshots and clones are a reason to use datasets. Plus, if you have a windows and want SMB (because NFS is hard to do on windows) you do not want files being accessed by NFS and SMB at the same time because SMB does collaborate on file locking.

I use NAS for backup of desktops. But I also want virtual machines and server like Plex and Home Assistant, etc, and I want them in their own dataset space.

Further thoughts: First thing I plan to do when creating the first NAS test bed is to see if the superuser can cp directories in dataset A to directories in dataset B.

I am used to different users having their own private file space in their home directory and see no need for anything else to separate them. Datasets seems like something that comes from non-nix operating systems. Nix has been great for 40+ years and there is no need to overcomplicate it. Debian is debian is debian.