Having just heard of bcachefs when reading this article, I tried to understand what makes it better than other existing FS but couldn't quite find a clear answer. It feels like it's feature set is equivalent to ZFS.

Do you guys know why someone should get excited by bcachefs?

Working deduplication would be amazing! ZFS has deduplication, but every time I've tried it has ended in a world of pain. Maybe they've fixed it in a more recent release, but the amount of RAM required for deduplication always outstripped the amount of RAM I had available to give it (the deduplication tables have to reside in RAM).

ZFS now has reflink support, which doesn't require lots of RAM, but isn't done automatically while writing. You need to run something like https://github.com/markfasheh/duperemove