All I need from a filesystem is to be able to mount it and read and write files.
APFS isn't writeable on Linux or Windows without additional drivers. Nor is HFS+. It's quite inconvenient. If ZFS was usable in that way, I'd consider it! But for now I still have to keep my boot volume as HFS+ so I can at least read files, and use FAT32 to shuttle data around.
