Absolutely. If you asked me to name current and historical filesystems on Linux I would 100% be able to name reiserfs - but features? Nope, not a single one. I was kinda surprised by the sibling comments that it has been THAT long. When it was actively in the news it was still unstable but promising. Then at some point it hadn't been mentioned anymore for a while and then we had ext4 and xfs and btrfs. So even as a linux user (and admin) I don't think it's anything anyone must know.