@darylsun the main benefit is you can securely message someone you only know by their online accounts or websites. It also lets you prove your account is associated with a website or another account officially. For example, my Keybase account proves cryptographically that I run the privacytools.io site and my Reddit username is /r/JonahAragon.

If you aren't like, even a semi-public figure the proofs probably don't make sense.