People care because it’s enormously better than SMS and also better than RCS. Nobody would care if green didn’t mean things like no guarantee of better than same-day message delivery.
People outside of the US have solved this problem by adopting an OS-agnostic Internet-based messaging platform like WhatsApp, Signal, Facebook Messenger, or Telegram. There are one or two people I exchange SMS messages with, but other than that, my SMS inbox is full of automated notifications, and the actual chats happen elsewhere.
So where does that leave the theory that iMessage’s “compelling edge and sole reason why people care about the blue/green bubble thing is being installed by default on iOS”? WhatsApp, et al. are not the default on any platform but appear to be doing fine.
WhatsApp et al. are doing fine and are the primary choice in Europe. But in the US, for some reason, people prefer not installing messaging apps, and instead keep the default messaging app, which means iMessage on iOS.
Most Americans have those apps installed, too, so it’s probably not the app being the default - as it is everywhere - but something else about social graphs. Looking at the data vs. SMS pricing 1-2 decades ago is one explanation I’ve heard but there are likely others.
