#2365: Messaging Systems explain

A Venn Diagram is shown, framed in a box. It has three components:

Vaguely Modern, E2E Encrypted, Supported By Everyone

Items Solely in the Vaguely Modern category are:

Facebook Messenger, Hangouts, Discord, Various DMs

Items In both ‘Vaguely Modern’ and ‘E2E Encrypted’ categories are:

Signal, iMessage, Whatsapp

Items Solely in the E2E Encrypted category are:

PGP Email, Various Obscure Projects, Skype I think, XMPP and XMPP + XEP-0384: OMEMO

Items Solely in the ‘Supported By Everyone’ category is:

SMS

All other categories are empty.

[Caption below the comic]: Why SMS refuses to die