ron RCS is basically a service by Google. Unfortunately it's the most widely adopted cross platform communication tool after SMS. RCS is presumably more private and secure as it's end to end encrypted in most cases. I personally would prefer RCS to not be run by Google, but it's still the case. You're certainly welcome to only use SMS.
Until we get wider adoption of Signal, this is my primary short message platform with most others, so I'm stoked on the attention the team put into the fix.