Because of the frequent communication difficulties between Android and iOS
Hiroshi Lockheimer, Google's senior vice president of Android, has proposed and helped Apple adopt a unified communication protocol called Rich Communication Services for the iPhone and iPad.
The protocol would replace standard SMS and offer improved cross-platform messaging capabilities. As noted, Apple has been slow in adopting RCS, so Android and iOS users are having trouble communicating via SMS. Lockheimer suggests moving away from standards within each company and creating a single protocol for broad, high-quality communication.