By your question you seem to assume that 1st reflection points are correctly treated by using panels etc. I suspect that there are other and, perhaps, better ways and this is often just a band aid approach which facilitates placing the speakers too close to a wall.
It seems that many folks want the appearance of a super wide soundstage which is best effected by utilizing the first reflection point. When they do this, IMHO, the combination of direct and 1st point reflections contribute substantially to a reduction in clarity. And a reduction in depth of image as well. If you don't hear this, with or without panels, as you seem not to do, then perhaps you are listening for the wrong thing, i.e. 'brightness'.
Personally I find drilling down correct speaker placement and appropriate toe in are a far better solution to the problem of side wall reflections than just putting a foam panel on the wall, etc.
FWIW.
It seems that many folks want the appearance of a super wide soundstage which is best effected by utilizing the first reflection point. When they do this, IMHO, the combination of direct and 1st point reflections contribute substantially to a reduction in clarity. And a reduction in depth of image as well. If you don't hear this, with or without panels, as you seem not to do, then perhaps you are listening for the wrong thing, i.e. 'brightness'.
Personally I find drilling down correct speaker placement and appropriate toe in are a far better solution to the problem of side wall reflections than just putting a foam panel on the wall, etc.
FWIW.