The emergency contact needs to be a key holder to have the means to decrypt the original account’s data. The easiest way to do that is to keep it in the same ecosystem controlled by proton, otherwise you’d have to distribute decryption keys together with the emergency access. That would make it possible for users outside of the ecosystem to participate, but would add the added complexity of having to store the key safely.
Except that emergency contact has to have a proton account… Sure that’s free but still, why the added constraint ?
The emergency contact needs to be a key holder to have the means to decrypt the original account’s data. The easiest way to do that is to keep it in the same ecosystem controlled by proton, otherwise you’d have to distribute decryption keys together with the emergency access. That would make it possible for users outside of the ecosystem to participate, but would add the added complexity of having to store the key safely.