Still exclusive to Google/Samsung proprietary apps. AFAIK they also do extensive SafetyNet attestation checks, so it isn’t even possible requires a bit of work (see below) to use RCS on a custom ROM like GrapheneOS, CalyxOS, DivestOS, or LineageOS, or even a rooted stock OS. Unless that does a complete 180°, I’m sticking with Signal
For the lazy, three of his kids died before 30:
Worth noting the life expectancy when Mark Twain was born was about 60-65, so he did outlive the average by 10-15 years. But this is still more due to his children having tragic deaths rather than his longevity.