Well the video is a bit extreme and if you go that far off axis, with most speakers you start loosing the highs making things sound dull.
Extreme Toe In
In my search for a stable soundstage for 3 listeners I have settled on extreme toe in of my speakers. Amazing centered image for 3 people, huge and wide soundstage extending well outside of the speakers. It looks crazy but it sounds fabulous. No discernable loss of anything in the sweet spot. See
https://youtu.be/OBLNY68VwZw?si=Ay4Ed5_qevKW9TcK
Not my system but found this while researching.