What do you mean by "Apple only supporting iMessage"? If I want WhatsApp I use that app, it sends notifications, it can even ring my device for a call. Same w

What do you mean by "Apple only supporting iMessage"? If I want WhatsApp I use that app, it sends notifications, it can even ring my device for a call. Same with FB/Signal/Telegram/etc. The view that Apple is forced to support other protocols or networks "just because" is pure idealism. The history of technology and business is a "maze of twisty little passages, all alike" for longer than we admit. Interoperability relies on government/intergovernmental mandating of standards - if you leave it to industry you get patent encumbered formats (see H.265).