I can't really determine if you're making this blanket statement with sincerity or there's a level of trolling. If it's the former, I can't really take your opinion seriously if you think room acoustics have zero effect on the sound quality of a "good" hi-fi setup or that the same system can overcome bad room acoustics. I would suggest you do the following experiment before you stand firm upon the soapbox of certainty.
Take your system and set it up in the various rooms of your living situation. I suspect that the system won't be able to overcome the acoustical drawbacks of each room (bedroom, bathroom, living room, closet, garage) and be able to sound the same in each space. DSP software can only get you so far when it comes to room correction and dealing with reverb, signal delay, and non-ideal room dimensions.
If anything, the more expensive a system setup is, the more important acoustically treating the listening room and room correction becomes to take full advantage of what the system can reveal. If you're simply listening to music streaming on a portable Bluetooth speaker then yes, the room doesn't matter when it comes to the low sound quality bar you have set for yourself.