I've had btrfs loose my laptops root filesystem, it just wouldn't mount anymore for no apparent reason. This was ~6 or 7 years ago. Reading the fs with some rescue command worked fine, the ssd continued to work for a few more years after formatting.
I've also had a weird situation after that where a micro SD formatted with btrfs on my desktop PC wouldn't mount on a raspberry pi, and vice-versa the same micro SD formatted on the pi wouldn't mount on the desktop. This was apparently caused by a difference in the used block sizes, which were mutually incompatible.
So I'll quote myself on this.
But also, my server is running a btrfs raid 1 due to the flexibility for resizing and that has been just fine for a few years now. It's not black and white and with backups I am not really worried.
I've also had a weird situation after that where a micro SD formatted with btrfs on my desktop PC wouldn't mount on a raspberry pi, and vice-versa the same micro SD formatted on the pi wouldn't mount on the desktop. This was apparently caused by a difference in the used block sizes, which were mutually incompatible.
So I'll quote myself on this.
But also, my server is running a btrfs raid 1 due to the flexibility for resizing and that has been just fine for a few years now. It's not black and white and with backups I am not really worried.