Reboot I had done a search hoping this actually had developed an answer by now as some of these threads feel very open ended, or that no real answer has been provided outside of "not really sure, but you're gonna have to use Google Messages" vagueness. I don't particularly want Google on my phone and keep hoping maybe someone has had an "ah-ha" moment and figured a workaround to getting group texts from people in another messaging app. Currently I have Google Messages along with Play Services and Play Store installed on my owner profile so that I can continue to receive texts from people, but having those on along with all my other daily apps just leaves me uncomfortable, sandboxed or not.
I know "the point" of GOS is not about "degoogling" but I was really sold on the notion (thanks to what seems like a highly misinformed DeGoogle subreddit) that I could actually eliminate Google from my life and still be able to function and interact normally with all my contacts. As soon as GOS adds their own RCS, this will 100% be the case for me as I don't particularly need it for anything else.