This is the traditional workflow for PGP-encrypted email, and has been for decades. Protonmail chose to be incompatible with this established standard.
> Protonmail chose to be incompatible with this established standard.
They've supported receiving PGP-encrypted emails[1] and are working on IMAP support currently[2]. Would be nice for you to cite sources before making strong claims like "chose to be incompatible". Everything is a feature and needs time to implement.
This is the traditional workflow for PGP-encrypted email, and has been for decades. Protonmail chose to be incompatible with this established standard.