Samsung has access to Google’s RCS implementation I believe. All other apps need to implement RCS themselves, which no real messenger has bothered to do yet. Everyone is waiting for Google to open up their RCS API so they don’t need to go through the complicated RCS API and the real-world testing/verification process themselves.
Nothing but Google‘s is allowed to.
Samsung has access to Google’s RCS implementation I believe. All other apps need to implement RCS themselves, which no real messenger has bothered to do yet. Everyone is waiting for Google to open up their RCS API so they don’t need to go through the complicated RCS API and the real-world testing/verification process themselves.