(tldr; do you have to sit in “the chair” to properly experience a high end 2ch setup?)

A non-audiophile, music-loving, out of state friend of mine sent me this photo, telling me he got to hear this setup the other day and how amazing it was. He never sat down and there were other people with him that were talking in the room. How good do y’all think it sounded? Do you think you still get a decent enough taste of the sound quality, under those conditions? I tried explaining to him how he should have sat front and center, if he wanted to get the full experience, but he was so impressed with what he heard, that he doesn’t think it would’ve/could’ve been that much better. I told him some surface info about on/off-axis response measurements, but when he asked me “how much better?”, I couldn’t give him a layman’s answer.

So there’s my question - aside from the obvious (soundstage, transient details, etc), how much do people miss out on by not sitting in “the chair”? I’d think that bass would be the biggest difference, if the room didn’t have proper treatment (which are prob 90+% of rooms, including both of mine). It got me wondering about setups like this and people that have them to just fill a room. Will a $200k setup like this, sound much better than a $20k setup, if you’re just hearing it in the room? Or even a $2k setup? The law of diminishing returns has to be even more of a factor, if the music is never heard from the sweet spot, correct?