Comment by Larrikin

It's because SMS is simply inferior to Whatsapp, Messenger, Instagram, Line, kakaotalk, Snapchat, Signal, etc unless you own an iPhone. All of them are cross platform and aren't intentionally broken for people who don't have or use iMessage. I personally avoid giving out my phone number as much as possible as all the other platforms have much better tools for communication, blocking, media, etc.