RCS is just a standard, much like how SMS is just a standard. Google's Messaging app is just one implementation of it, though it probably is the most popular in the US it is not the only one, nor is Google able to decide who cannot use it. Carriers typically have their own, though you may have recently heard that T-Mobile decided to switch over to Google's.
RCS is just a standard, much like how SMS is just a standard. Google's Messaging app is just one implementation of it, though it probably is the most popular in the US it is not the only one, nor is Google able to decide who cannot use it. Carriers typically have their own, though you may have recently heard that T-Mobile decided to switch over to Google's.