Speaking of TrueNAS, in theory ZFS is a lot better for long-term storage. The ARC (RAM caching) and L2 ARC (SSD caching) means that there's a lot less wear on the drives.

My TrueNAS Scale box has 16GB of RAM and a 1TB SSD as a cache. If the SSD fails, it doesn't really matter: the data is always checked against the checksum (as I understand it). If the drive fails, it just uses the backing storage or the ARC.