That's a pretty uncharitable way to interpret the statement, when the three features OP mentioned are a part of literally every modern messaging platform that people use. Not just iMessage and RCS (the open protocol which is the best analog to iMessage), but WhatsApp, Signal, Telegram, Discord, Messenger, Instagram, Slack... It's actually hard to think of one that doesn't. I guess IRC, if you consider that in any way comparable to the others, but it really isn't at this point, being a now fairly obscure protocol reserved mostly for tech-savvy people and niche cases.