Filesystem Development Considerations
Considerations for default file system choice for Kicksecure.
Btrfs has been deprecated by redhat.
default in openSUSE
stratis is not in Debian afaik.
But there's some stuff about "plain" ZFS.
Says ZFS is Oracle and I am not amazed by how Oracle maintains VirtualBox.
Also ZFS is not going to be mainlined in Linux due to licensing issues.
There is also OpenZFS but apparently not in Debian.