Synology is like Ubiquity in the self-hosted community: sure it’s self-hosted, but it’s definitely not yours. End of the day you get to deal with their decisions.

Terramaster lets you run your own OS on their machine. That’s basically what a homelabber wants: a good chassis and components. I couldn’t see a reason to buy a Synology after Terramaster and Ugreen started ramping out their product lines which let you run whatever OS you wanted. Synology at this point is for people who either don’t know what they’re doing or want to remain hands-off with storage management (which is valid; you don’t want to do more work when you get home for work). Unfortunately, such customers are now out in the lurch, so TrueNAS or trust some other company to hold your data safe.