This is what I meant. ☝️ If they had merely wrapped LVM/mdraid or ZFS in a nice packaging my argument wouldn't stand. They would have had equivalent data reliability to TrueNAS.

As a software developer (who's looked at ZFS' source to chase a bug,) I would not dare to write my own redundant storage system. I feel like storage is a complex area with tons of hard-learned gotchas, and similar to cryptography, a best practice is to not roll your own unless truly necessary. This is not your run-of-the-mill web app and mistakes eat data. Potentially data with bite marks that gets backed up, eventually fully replacing the original before it's caught. I don't have data for this but I bet the proportion of Unraid users with eaten data from the total Unraid userbase is significantly higher than the equivalent for solutions using industry standard systems. The average web UI user probably isn't browsing through their ods/xlsx files regularly to check whether some 5 became a 13.