SMS (text) messages are better than email. They receive an open-rate that is four-fold higher than email, a number that increases when a recipient has text message reminders activated. Messages are read, on average, within four minutes of receipt.
Additionally, every mobile phone can receive SMS messages, whether it's a basic flip-phone or a modern smartphone.
We want our users to be able to communicate with anyone they want, and SMS is a universal messaging standard that doesn't require the recipient of an alert to do anything on their end.