Another use is the ability to actually own your own domain name (instead of rent it).
“I really hate suffixes, so I want my address to be myproject and not myproject.io”
“I have a business idea which requires me to be a TLD, but I don’t have a ton of money to pay for it”
“I don’t think ICANN dispute resolution process will work in my favor, so I would like to get a domain name not subject to it”
“I think the blockchains are the future, and I really want people to use them”
...but I think they either have a better solution, or not worth trying to deploy yet another domain name system.