While I agree with you on the topic of stickiness, I would like to mention that FaceTime now supports calls to Android devices. Regarding the bubbles, I can’t say I really understand the issue. I’ve had both android and iOS devices and the bubble bit has not been an issue that has kept me from interacting with friends and family. I think group chats between android and iOS had some issues pre-2016 but in my group chats I haven’t noticed any issues.