Ok, when or why would you use IPFS instead of something else?

lol, you can troll better than that, c'mon :)

Are you just unable to answer the question or are you just so new to the interwebz that you think that was a troll?

ZFS is less flexible in deduplication because it's not true content addressing, and git has lousier protocol. Rsync and unison also have lousier protocol and don't deduplicate storage.