I don't buy this. Customers needed no convincing from Apple. Even where iOS isn't dominant they saw their dropped and expensive SMS/RCS messages and picked up whatsapp.
Carriers like AT&T and Vodafone that were early to adopt RCS never even managed to interoperate with other RCS carriers - you could only send RCS to other AT&T subscribers, or other Vodafone subscribers. Then they all gave up and just adopted Google's servers. So now RCS just means "Google Jibe".
It's a failed standard. It never worked.
It doesn’t fix the end to end encryption problem unless google opens up their system.
Huh, pleasantly surprised Apple is taking up the mantle on something cross-platform. Nice.