Sauce? (I highly doubt that anyway. Last time i checked, it wasn't even close. But that was a while ago)
Discussion
linux supports root btrfs filesystem. I've been using it for many years. Yes it was unstable in the beginning but I haven't had any problems for several years.
I used Btrfs for years as well. Great if it's reliable.
The question was how does it compare to ZFS. Performances, features, stability, recovery, license, etc.
A few years ago, ZFS was vastly superior. Today IDK.
Highly controversial topics anyway, from what I see online...