Let me ask a question. My understanding of the (rather convoluted) language of this article is the following:
Proton Mail simplifies PGP by making it automatic and hiding it behind its user interface, however this is only true for two Proton Mail users mailing each other.
As soon as a Proton Mail user wants to exchange email with a non account holder, he is back to the good old tedious way of using PGP. (Barring a special mode where you give a password offline to the intended recipient, and he logs into Proton’s server to read your mail. But you don’t need PGP then : Tutanota works exactly that wey.)
This negates the whole advantage of simplifying PGP, because:
There is an exceedingly remote chance that a random individual or organization you want to exchange email with has a Proton Mail account.
There are a few exceptions, such as you persuading a few friends or family members to subscribe at Proton Mail, or your whole company deciding to use Proton Mail for internal email.
However, at that point, it does not matter that PGP is used rather than something else. Tutanota of course encrypts all email exchanged between two of its users, and it does not need PGP for that.
But the default situation, when you would need to use encrypted email, is that Bob and Alice have different email providers.
Even if they both used encrypted email providers (say, Proton Mail and Posteo), they would still suffer the horrendous usability problem of PGP.
Agree ? Disagree ?