It has most of the major features of BTRFS + tiered storage + per file/directory redundancy + native encryption support. It also seems to be architectured in a way that avoids the write-hole issue for RAID 5/6 that BTRFS has and therefore once that feature is added, it won’t be as likely to eat your data. It also had a better system for handling different sized drives.
Overall, it seems like a redesigned BTRFS with the experience of bcache development and benefit of hindsight avoiding some of the early pitfalls that BTRFS had. It already seems like the ideal filesystem that does it all for single systems. Especially if Kent gets the backing he needs to fill out the rest of the roadmap, I really don’t see what other filesystems have to offer that are worth losing the other benefits.
Maybe I’m wrong and it will stall or something, but it has been almost a decade already and there have been steady improvements throughout. I plan to switch to it as soon as I can get it working. It is still a bit rough getting a proper multi-drive encrypted system booting since it is still early days of mainline support and disros don’t have very good support for it yet.
There are also 3rd party interfaces which are basically web client wrappers that add some features.