1. Identity. its the sum of your online presence.
2. Insecure devices. In keybase devices have unique keys and can can be revoked when lost
I have been trying Protonmail, they have been deploying gpg in browser and apps. The interface is nice and I would have no problem recommending it to my parents. The problem is that it currently only works with other Protonmail users. Once they allow adding public keys for contacts and searching keyservers/keybase it will be quite nice and useful.
They have no solution for the key security on the mobile phone. I personally dont want my key on my phone.
I would really like to see a product that interfaces keybase and protonmail. Nicely designed apps and webinterface that all have different keys. Directly integrated with my social media contacts.
Thanks to everybody working these problems.