Room acoustic treatment is surely rewarding in terms of sound or performance but to me it is not a necessity. It is nice to have if the space is a dedicated music or home theater room, or the acoustics of the room is poor. When I had a dedicated music/HT room about 15 years ago, it was installed with RPG Skyline diffusers, omnifussers and absorbers complete with bass traps at the front corners. After moving to a new place, the system is now in the living room without any specialist room treatment product. I now derive greater enjoyment from the new system in the untreated room than the old system in the treated room.
I have learned that one does not require room treatment to enjoy music from the system. For me, a clean and uncluttered look in the living or lounge takes precedence over a treated room that has a studio look.