I personally really like btrfs for my large media HDD because it makes copying large files an instantaneous operation.
Also, it’s useful to have 6 hourly snapshots in case *arr upgrades something or anything else happens (btrbk).
It’s not necessary almost any time, but the times I needed it a CoW FS with snapshots came in handy.
Edit: Also, btrfs does check summing, so it’s possible to detect bit rot.
For no particular reason, except for btrfs taking up less RAM. I don’t know their specs, but the lack of RAM was my reason for deciding against btrfs for my large non-mirrored HDD.