Comment by delroth

It's not (only?) a question of "gaining value". End-to-end encryption is fundamentally incompatible with many features that Gmail users rely on. I would recommend reading https://moderncrypto.org/mail-archive/messaging/2014/000780.... from an ex Gmail anti-abuse tech lead. And for 99.99% of Gmail users, protecting automatically against untargeted phishing and malware attacks is a larger security improvement than having e2e encryption.