I do streaming with a 5.2 system in an open-concept living room. I was debating the same as well when we had purchased our current residence, especially since I knew I would be putting a two-channel system in another room. We went with on-wall front R, L, and Center speakers with in-ceiling rear speakers - this reduced the footprint quite a bit. Subs are flush with the credenza. I, too, came from a sound bar, which was great for dialogue but not exactly immersive.
I mirror another member here; more time is spent watching television and movies than listening to music in my 2-channel system - primarily because I’m with the spouse when watching in the living room. My preference will always be 2-channel, but watching television with a 5.2 is the reality 80% of the time.