I think I can agree with that. Unfortunately PGP is the only alternative we have for emails (i.e., the client-side tools would still be doing PGP encryption), which is also the reason why it shouldn't be used for really delicate communication. The fact that - whatever setup you use - there will always be metadata showing that person X communicated with person Y alone is a nonstarter for certain types of communication.
Signal would be my recommendation.
Thanks, I appreciate it.