I had never heard of RCS but as soon as I read "RCS requires carrier cooperation" I thought "They're doing it wrong." This sounds like they're taking the worst

I had never heard of RCS but as soon as I read "RCS requires carrier cooperation" I thought "They're doing it wrong." This sounds like they're taking the worst misfeature of MMS and doubling down on it. What happens when you take an application and specify its protocol too low in the 7-layer stack? RCS, apparently.