Sure but maybe they don’t want to use btrfs. Ever thought about that?

No, please research what deduplication is before commenting.

https://en.wikipedia.org/wiki/Data_deduplication

You might be thinking of incremental backups which also saves space but is not the same thing.

If you for example ran deduplication on a file server and a bunch of users uploaded the same files in multiple different directories, deduplication would remove all duplicate copies and just link them together. This has nothing to do with snapshots. btrfs might support deduplication but now this software does too. Your comment was completely unnecessary since not everything in the world can or should run btrfs

I use it to communicate with my family

It’s more convenient than chat apps.