If you want RCS, you have to go with one of the corporate apps like Google Messages or Samsung Messages. It's sad and I hope the situation changes eventually because RCS is much better than SMS and more ubiquitous than signal.
There may be a few others that handle RCS besides those two, but their ties may be just as unsavory as the first two.
That's pretty awesome that there are at least some laws about telecom provider privacy where you are! Here in the states they can basically do whatever they want with whatever you give them 😓