To be fair to Google, though, they did not intend to operate this as a SaaS. They fully expected carriers to run their own RCS servers but almost none did, so

To be fair to Google, though, they did not intend to operate this as a SaaS. They fully expected carriers to run their own RCS servers but almost none did, so stepping in to fill the void was a follow-on decision from Google (which was honestly a very smart move - Messages w/RCS is hugely improved over vanilla SMS) only after realizing carriers didn't have the appetite to abandon SMS.