My experience as an iPhone user in the US is that it's like pulling teeth to convince older Android users to install a third party chat app. They refuse to participate in the solution; they don't even know there's a problem. Most Android users I know are old people. I'm basically on my knees begging them to pick an app, I'll install literally anything. They won't do it. It's not worth the hassle to even try convincing them. Green bubbles it is.