SMS is considered as really obsolete in Europe, even older people use WhatsApp. I think I have not sent a single SMS in the last 2 years. In Asia there are other services like WeChat (China) or Zalo (Vietnam) that are really popular, it really depends on the country. Sending an SMS feels like sendig a fax.
Regarding iMessage, I guess it's the same as BBM in the late 2000's, if you don't have it people might consider you are not cool enough to talk to them.
Regarding iMessage, I guess it's the same as BBM in the late 2000's, if you don't have it people might consider you are not cool enough to talk to them.