RCS existed as a concept, but was extremely flawed and underfunded. Carriers had zero interest in changing from SMS at the time. Apple tried, and gave up, instead choosing to build iMessage. You may recall that when it was announced, it was actually touted by Steve Jobs as an open protocol; that never materialized, largely because Apple realized how massive of a lead they had on every other handset maker because they weren't beholden to the whims of the carriers, who had decided not to move on RCS for many years.
I don't believe Apple ever said iMessage would be an open protocol. It was Facetime that Jobs announced as an open protocol (as a surprise to everyone else inside of Apple), and supposedly that never materialised due to patent BS.
Those are just a bunch of unproven claims. An alternative theory is that Apple rejected RCS in favor of iMessage because vendor lock-in boosts their US profits.
I was alive and recall the reporting at the time? I don’t have the energy to find sources right now but my memory, while not perfect, is pretty certain this isn’t the Mandela effect.
I also worked at Apple in 2008, and recall the discussions then too.
