As someone points out in the comments section of article, green has been the color of SMS since the first iPhone (which didn't have iMessage) [1]. It is still possible that they made the green "harsher" or something.

I think all those Tweets about "green bubbles" can be seen as a reminder of how society works: status signalling explains a lot.

We should make some kind of an NFT t-short which certifies each person's net worth. People can simply wear a t-shirt displaying their net worth in a large, hyperlegible font and get done with it. /s

[1]: https://images.macworld.com/images/legacy/2007/06/images/con...