There is a distinction to be made between casual, home-user level data preservation, and "pretending to be an important business with mission critical datastores" preservation.
Sure, building an enterpride-grade server with a $500+ supermicro motherboard, four redundant premium PSUs, ten $5000+ clustered UPSes and sextuple mirrors + PLP for every single SSD I dare to put in the server might be better for data preservation, but I just don't care enough for that.
For me, TrueNAS is just another way for me to store files over the network, except safer and more robust than my hypervisor, even when virtualized.