I want to learn more about file systems from the practical point of view so I know what to expect, how to approach them and what experience positive or negative you had / have.
I found this wikipedia's comparison but I want your hands-on views.
For now my mental list is
NTFS - for some reason TVs on USB love these and also Windows + Linux can read and write this
Ext4 - solid fs with journaling but Linux specific
Btrfs - some modern fs with snapshot capability, Linux specific
xfs - servers really like these as they are performant, Linux specific
FAT32 - limited but recognizable everywhere
exFAT - like FAT32 but less recognizable and less limited
ZFS is completely different than XFS. XFS is like a better (different?) ext4. ZFS is an error-checking software raid COW filesystem that does snapshots and can have multiple replicas, both local and remote. It uses zvols and datastores. Think btrfs on steroids and with a working raid subsystem.
It's got a weird semi-closed license because Oracle is involved but it's never been enforced and at this point is in such widespread use in large and small enterprises that it would be impossible to enforce.
OpenZFS is under a completely FOSS license but it's incompatible with the GPL and can't really ever be merged into the Linux kernel. The workaroundids to provide it as source code which gets compiled as a module every time there's a new kernel via dkms.
More controversially, Canonical ship OpenZFS pre-compiled in Ubuntu which some lawyers believe to be infringing on ZFS' codebase.
Honestly the OpenZFS situation on Linux is probably the biggest single reason for the growing interest in btrfs and bcachefs, the former slowly becoming default on more Linux distros over time and lots of investment from SUSE and Facebook AFAIK.