TrueNAS ensures that different versions of different software fit together. So you update your OS, and your setup doesn’t break.

The common tasks are made easy: snapshot scheduling, snapshot replication, Samba share with a few clicks, backup to cloud, users management, one click install of applications, SMART tests, etc. Config management can be a headache.

I use zfs-auto-snapshot for snapshots, it works great. I think the only thing I would want is early warning for a disk failure. I'll probably automate that. TrueNAS feels extremely heavy with too many features I don't need. There is a web server, database, etc which feels overkill for a simple home NAS IMO and having to manage the management system.

The only other thing, you may be forgetting, is an app you never knew you needed.[0] ;)

[0, an interactive, file-level Time Machine-like tool for ZFS]: https://github.com/kimono-koans/httm