I've been using email since 1992 in a huge variety of work, study and personal contexts. I installed PGP now and then in the '90's out of curiosity but never sent a single encrypted email as I never came across any recipients with it installed. I have never had anyone request email encryption. I don't know what the expert consensus is. But the user consensus is that PGP is invisible, and will never be used outside of a few tiny niches.