

Google’s own one may be, and that is their right, but it is an open standard so anyone can produce their own RCS app like Samsung has done, and the same way Apple is building support into their exiting app. Nothing should stop a 3rd party developer looking at the standard, and producing an open source RCS app?
Not really so, as MSMS is a major thing by us (outside the US) for most notifications from banks, gov, transactions, visit to pharmacy, etc. Incoming is fine apart from fact it is all open for anyone to read, but replies cost money. Also, where people are not using the same messenger, then it is sms text messages, each costing money. For pre-paid phone accounts, those SMSS messages cost even a bit more. SMS today is still the common denominator everything falls back on. It is very expensive when you consider what is paid, and it is only around 140 characters vs data.