xfs has reflinks. That means you can copy huge wodges of data nearly for free on one filesystem. For backup systems this is a killer feature. Veeam rolling up incremental backups into the last full happens in seconds because pointers to blocks are juggled around rather than the data blocks themselves.
xfs has been around for a very, very long time. I use it for larger filesystems eg Nextcloud, Zoneminder and the like (and Veeam backup repos that are not object storage). I use ext4 by default.
pfSense boxes - zfs because the alternative is ufs.
RPi - OverlayFS (with ext4 and tmpfs) gets you a generally read only filesystem with changes held in RAM. Ideal for kiosks, appliances and keeping memory sticks alive.
Windows - NTFS, it works well and has streams and there aren’t many other options (ReFS is a bit new but it does have reflinks)