I bought a UNAS-2 (and a couple of 12 TB IronWolf Pro drives) a few months ago when the "time capsule will not be supported in a future version of macOS" warning first appeared. It has been outstanding alongside the rest of my UniFi setup, and perfectly supports Time Machine backups. The UniFi Identity macOS app means my family's computers always stay authenticated/connected and my wife & kids don't have to do anything to make Time Machine just work.
If you're a power user who loves the Apple aesthetic and you already have a UniFi setup at home, you'll feel right at home switching from Time Capsule to a UNAS.
Also why the 12TB ironwolf drives specifically ? Personally I always was a fan of buying true enterprise (the ones designed for "online" or near line storage) but sometimes specific models and sizes of random drives do very well in Backblaze testing