No one has disputed that.Stereo was picked from the Greek language because of it's meaning of solid or three dimensional "before vowels stere-, word-forming element meaning "solid, firm; three-dimensional; stereophonic," from Greek stereos "solid" (from PIE root *ster- (1) "stiff")." hxxps://www.etymonline.com/word/stereo-
The whole point of a stereo system from the very first experiments until now has always been to reproduce a soundstage laid out in width and depth. There is no point having a stereo system if you are not able to reproduce an image with depth and width. It doesn't even have to be "HiFi", you can reproduce a solid image in depth and width with a relatively noisy and distorted system that does not have a great deal of bass or treble!
HiFi might be about trying to reproduce the widest, flattest frequency response with the least amount of noise and distortion, but you can do that with one speaker! If you have two speakers and are listening to 95% of commercially available content, then you are listening to a stereo source and for that to be properly reproduced, it MUST have soiid image defined in depth and width.
It is pin point instrument placement I don’t believe in - not depth and width, but it seems to me that folk here just pick and choose which parts of other peoples posts the wish to take any notice of.
Try re reading what I actually said.