The iMessage app does both SMS, and the iMessage protocol. Apple could have released an android app to let you have blue bubbles on android and communicate securely without any of the constraints of SMS by simply releasing "iMessage for Android".
Somehow Signal, Whatsapp, Telegram, Discord, WeChat, LINE, KakaoTalk, etc etc all manage to have both iOS and Android apps that can message each other, but for some reason the richest company in the world, Apple, cannot manage to port its chat app to one additional platform?
It is 100% Apple's fault that messaging between iOS and Android has had so much dumb "green bubble" friction.
Apple's conflation of the SMS and iMessage protocols has also made it harder for people to realize what's happening. Frankly, Apple should have had two apps from the start (Text Message and iMessage), one of which only spoke SMS, and the other of which only spoke iMessage.
Btw everyone knows whether they're using iMessage or SMS, that's the whole bubble color thing.
Everyone sorta knows, but because iMessage "feels" like it's just the native messaging app on the phone, it makes people feel like the issue is android (why don't android phones come with this super-sms built in?) rather than apple for not making the app available broadly.
If it were a separate app, then perhaps the EU would have regulated "when setting up iOS, you must get a default option between iMessage, Whatsapp, Telegram, Signal, etc, you must be able to change the default messaging app", and forcing people to install it would make it more obvious that this is Apple implementing a proprietary chat protocol, not Apple just doing SMS better than android.
> they didn't create the problem. And they're not a charity.
Apple did create the problem by creating a walled garden messaging app, banning beeper for implementing the iMessage protocol for android, and tying some of the phone's core functionality to this built-in app in an anti-competitive way.
A certain amount of industry interoperability should be expected. If you make a browser, it should be able to load competitors websites (which nice, safari can load google.com, good work). If you make a computer that can install arbitrary software, you should allow anyone to install software they wrote freely (oops, apple missed that one). And if you make a messaging app or social media app, you should make it support all major operating systems people use so that people can switch their operating systems and phones without losing touch with their friends. I should still be able to facetime my grandma even if I switch to linux because gosh knows she's not going to learn a new video call app.
Maybe RCS between Pixel phones is ok, because that's not the same thing, it goes through Google's servers only. And that was also the only way you got E2EE in RCS until very recently.