But if someone messages me from iMessage, I can only reply via old school SMS/MMS because Apple won't allow any non-Apple users access to their IM platform. This is incredibly annoying and well established as an intentional selling point.
All I hear is "if you want me to really listen to you, then you need to buy a specific brand of device."
A "green bubble person" is just someone forced to use crappy fallback measures because your preferred messaging platform wants to be exclusive. I'd gladly install iMessage (as I've installed many other IM apps) if it was an option, if only so I could stop the endless complaints about "green bubble people" ruining everyone's day.
All my friends on Telegram have iPhones and Android. Oh, and Telegram is objectively a better experience from a UI and UX standpoint than iMessage. And it's more reliable and much faster when sending images or videos, and does not randomly convert my links into obnoxious previews. I don't mind spending ten seconds installing the app _and_ making an account (since that's literally how long it takes) to get that experience.
If only it was fully e2e encrypted, but maybe that's why it's so frictionless. OTOH, e2e encryption is weak when you have groups, as anyone can enter public groups, and a compromised participant in a private group can read everyone's messages.
iMessage doesn't interact with SMS just like normal — the Messages app does. It just switches between SMS and iMessage based on the recipient.
1. iMessage interacts with SMS just like normal
2. It gives you the "blue bubble" which is a sign of higher class, because you have the more expensive iphone platform.