Outside of a few niche hardcore technologists, nobody knows what PGP is or how to use it. It would be hard enough getting my mum set up to PGP sign her own emails in Outlook, on the desktop and from her phone. (Is that even possible?). Let alone require anyone emailing her PGP sign their email too? Thats never going to happen for so many reasons, both technical and social.
I'm a software engineer and I tried setting up PGP years ago in thunderbird and it only worked for a few weeks, then it somehow broke. And then later I lost my PGP key. Oh, and then I started using webmail and PGP didn't work there at all.
And then later still I realised my public PGP key (signed by my web of trust) leaked details on the identity of my social network; which bothers me a lot more than any problems I've personally ever had with a forged identity.
PGP is dead. Let it go.