What most are saying is that there’s always been the perception that comes with green messages. When I was on Android (pretty much since the first Nexus all the way to the Galaxy Fold 4), I definitely noticed iPhone users avoiding SMSing with me or in groups, and instead using Facebook Messenger because of the issues that come with group texts involving non-iOS users.
Now that I’m on iOS, I’m aware of the differences, although I don’t particularly care since so many Android devices support RCS.
Then they should buy an iPhone if social posturing is important to them.
In all seriousness now: the green buble shows you that you’re sending SMSes which, based on carrier and/or country it can cost you, especially if you’re roaming overseeas where every SMS is 10/20/50c each.