You make a fair point here. The pressure to just buy an iPhone so you can use iMessage is frustrating and downloading a third party app is really easy (and possibly a better option than iMessage) but you gotta remember most people don't think like that. Honestly, I use signal for most of my messaging but still need to use text for many of my family members because I'm not about to walk my Dad through downloading, setting up, and using a separate app just to text me.

Also, yeah Apple could make iMessage available on Android but in the same vein Nintendo could make games for Playstation/xBox. They could, but why would they? People buy their hardware for the specific software that is offered. It's frustrating but that's part of their business model.

The real solution is to replace SMS/MMS with a better solution, which RCS is attempting to do, but it's sub par compared to anything else still, in my opinion.