Good that you mentioned that. Reminded me that I have an Arch Linux install here where I forgot that I did choose BTRFS during installation. Within maybe a month I noticed FS errors. Looked scary. Nervously searching for documentation was even more scary :
wiki.archlinux.org/title/btrfs#btrfs_check -> This article or section is out of date. (Discuss in Talk:Btrfs) Warning: Since Btrfs is under heavy development, especially the btrfs check command, it is highly recommended to create a backup and consult btrfs-check(8) before executing btrfs check with the --repair switch.
What is this? My beloved Arch Wiki is not 100% perfect!
Then found this :
WARNING: Using ‘–repair’ can further damage a filesystem instead of helping if it can’t fix your particular issue.
Do not use --repair unless you are advised to do so by a developer or an experienced user, and then only after having accepted that no fsck successfully repair all types of filesystem corruption. E.g. some other software or hardware bugs can fatally damage a volume.
I figure this explains the popularity of BTRFS snapshot configurations. Luckily I had some backups :)