It seems like the main issue is BTRFS has some sharp edges: it's possible to use it in a solid way, but there's enough situations you can put it in where it com

It seems like the main issue is BTRFS has some sharp edges: it's possible to use it in a solid way, but there's enough situations you can put it in where it completely fails that it's really hard to be confident deploying it unless you're really going to be very careful (and, to be fair, for all of ZFS's reputation, it also has a few sharp edges, but they seem to be more corner cases with certain combinations of features as opposed to pretty common use-cases. Heck, btrfs has had a corruption bug in the last two linux releases that's only just being fixed).