

S/MIME is insecure, outdated, depreciated, and should be discontinued; yet people don’t want to adapt or grow or change.
Because some organizations do use S/MIME; all email software is required to implement it, that is if they want to be adopted and used by said influential organizations.
OpenPGP and PGP in general is secure but suffers from usability issues and is often wrongly painted as user-unfriendly. (it’s really no worse than S/MIME, installing and managing keys is exactly the same hassle as it is with S/MIME.) The main issue is that some people are too lazy or resistant to change to adapt to it.
Get Ready, Player 2!