I honestly don't see the point of Btrfs. ZFS is more mature, more stable, better defaults, etc. The only reason Btrfs existed was because ZFS wasn't GPL. But now we have a way of running ZFS on Linux Btrfs seems utterly redundant.

I mean I'm all for choice on Linux but when it comes to file systems I'd rather have fewer choices but those choices be absolutely rock solid. Btrfs might have gotten to that stage now however it's eaten enough peoples data (including mine) over the years that I can't help wondering why people bothered to persist with using it when a better option was available.