You’re probably an adult, the whole blue/green bubble is targeted at high school student demographics, ya know, the same demographic who LOVES pointless drama and bullying over stupid shit like the color of a text bubble
Apple likes this setup because by the time you leave HS you’ll probably have switched to iPhone due to peer pressure and are unlikely to switch later because “it’s just what I’ve always used” and like you’ve noted no longer care about the blue/green bubble debate