Google wants us to pick theirs over Apple's. Also note that to my knowledge, RCS is not available in all countries.
The other funny thing is that Google complains about SMS being insecure -- all while RCS does not support end to end encryption. Google Messages added that feature recently relatively (last year? please correct me below) and I still can't understand if it's on by default or not.
Here is a random article about RCS state. Feel free to google for more: https://linustechtips.com/topic/1327240-in-the-us-rcs-text-m...
I would love a common solution, but rationally I can not blame Apple for keeping a (to me from experiencing both) superior experience that brings in customers. And Google has just managed to catch up. Google will need to make their messaging an order or two better, to the point that Apple will have to join.
P.S. Also, I am skeptical any time the phrases privacy, end-to-end encryption, and Google cohabitate the same statement.
(Edit)P.S.2. Just use https://apps.microsoft.com/store/detail/bluebubbles/9P3XF8KJ... in the meantime.