I just left an online review for a business.
Has Mojeek considered allowing users to post business reviews? This might add value for businesses looking to advertise on Mojeek.
It might be worth looking to see what authentication schemes FIDO2 allows. It might be possible to set up an authentication scheme where all the personal details are optional. Then, if someone chooses to leave their contact information blank, they will just have fewer recovery options. For example, they might only be able to recover their account with a spare YubiKey that they previously registered.