Only half kidding. The real issue is just SMS vs data. And a little bit of feature parity - it's changed a few times, but until recently, if I "liked" a message in an SMS thread, we'd all see something like "Alistair like 'something said by somebody'" instead of just applying the thumb-up icon. This only gets worse for media sharing, link shares/snapshots, etc.
From what I understand (I am European, so never met anyone using iMessage) the real issue is that Apple refuses to distribute its application on Android, forcing instead communication from and to Android to travel via SMS. It's not a problem of SMS (which nobody really uses anymore), it's a deliberate choice. The genius is to allow enough communication between iPhone and Android as to not force iPhone users to switch app, while making it as uncomfortable as possible for both sides.
If it were possible at all, the best solution would be for Android to just block SMS from iMessage, citing some bogus security reason. Then iPhone users would be forced to switch app to communicate and the spell would be broken.
I really like my current android device, but my wife and our friends have iphones and we are all constantly inconvenienced by the messaging and other poor sharing options between platforms.
They share things without having to think about it, and I have to come up with solutions that are acceptable to them.
Between this issue and the differences in performance in the last few years, it has me thinking of moving back to team blue after 10+ years on green.
I've switched largely to communicating over alternative platforms since text messages can be unreliable.