Btrfs-rec: Recover (data from) a broken btrfs filesystem
lukeshu.com
lukeshu.com
Considering btrfs doesn't have a working RAID implementation, screwing up a drive would lead to the volume being unusable, yes.
(Raid 5 and 6 are a different story, but frankly I think it's silly that modern systems talk about them at all, instead of general purpose erasure-coding.)
[0] https://kb.synology.com/en-nz/DSM/tutorial/What_was_the_RAID...