If you think that something extremely basic seems something that is hard to grasp for other people, it's usually because you're misunderstanding the situation, not because other people are failing to grasp the extremely basic thing.
That's not what's hard to understand. It's choosing to exclusively use iMessage knowing that not everyone can use it. And then shifting your social circle based on one company's decision to not support it on other platforms.
Statistically, sure, but it's not evenly distributed across regions and cultures. People can find themselves in social circles where iMessage is the norm and be pressured into using it because others are unwilling to install a second messaging app.
For years it meant fewer features and frustrating experiences in group chats.
Kids liked renaming group chats and liking/reacting to individual messages, and sending higher-res photos, and one "green bubble" participant nerfed the whole chat for everyone.
In spite of Apple knowing kids got bullied over this, meh, money. Thankfully this has now been just about fixed (depending on which Android version/carrier someone has), so green bubble stigma should be on its way out [eventually].
Firmly believe no one ever actually cared about the color.
How has it been fixed? It's still just Apple parsing the messages that came through like so and so reacted with some emoji to some message, and then attaching it to that message. But then this doesn't work with reacting to attachments like photos as it doesn't know which photo was reacted to.
