IMHO RCS should have not being adopted unless it has encryption built in, or else it is just Google's iMessenger.

At this point, anything messaging platform or financial transaction platform that doesn't implement post-quantum encryption + classic computer encryption ECC (such as superdilithium) should NOT be consider as a standard for messaging for the public. All that ought to be part of the messaging protocol, so we don't end up with GSM 64 bit encryption mess.