Why do you find this surprising? The #1 key to imaging is simultaneous arrival. Speakers in phase and perfectly equidistant is mainly what does it. This is why you can hear imaging from a laptop.
Move the speakers too far apart and two bad things happen. One is the direct sound from the speakers fades relative to room reflections. The other is the sound coming more from the sides starts to be like headphones. Instead of being in front of you where evolution is telling your brain it should be it starts to sound like its inside your head. So of course the effect starts to break down.
This already is more than enough information to figure out the rest. Anything sound reflective competes with the direct sound from the speaker and diminishes the effect. The bigger and flatter and harder the more reflective and worse it is. This is why its so important to keep speakers away from side and front walls.
Or if they are small and close then the same goes for the desk top. Or in a living room situation a coffee table is a lousy thing to have.
Equipment rack, TV screen, same deal. Take a look at this
https://systems.audiogon.com/systems/8367Front and center between speakers is the worst place, so the amp is down low on the floor and back farther than the speakers and there is no rack, except the turntable stand, which is located even further back and off to the side.
There’s a huge amount more that goes into getting crazy good you are there imaging but having the speakers far away isn’t really an advantage at all, at least not in any way I can think of. And I am all over this like white on rice.