Is soundstage DEPTH a myth?

You don't need to spend a lot to get soundstage or depth. First time I heard it was with in the1980's Marantz 2035, Pioneer turntable/Shure cartridge and Advent speakers. Of course the more money you spend the better it is. My Harbeth 30.2 and Luxman integrated do way better.

Funny thing is, I recently listened to several songs on a well-known $12K DAC and $20K speakers and the imaging was very wide, but the height and depth was barely there. So money isn't everything.

i will put this here - given the topic being discussed it is worth a watch i believe, specifically for the comments in the second half around how the speakers need to be well into the room to get the proper depth of image

the rest of video is just ok, these two are not among my favorite folks on y-t, much of their content is pretty worthless, but in this particular case, i think their discussion around how speakers image is spot-on and very salient to this thread

https://youtu.be/GTwwvY8Is1o

In my humble experience : speaker placement is the biggest factor of hearing (and reproducing )  the “depth” from your source of music.  In most cases if your speakers are placed too close to the front wall of the room you tend to have a rather flat sound image ( no depth). Regardless of how expensive the gears are. 
 

Try to pull your speakers 12 inches forward and see if you hear a difference ? 
Have fun and enjoy ! 

Try listening to more mono music and tune the room to that. It does exist.  

I have perceived varying levels of soundstage depth in recordings themselves and in the way the music is presented via my equipment.
Much improved speakers revealed this.
My response was something like, “wow, the distance between those cymbals and the lead vocal seems physically pronounced.”
I find soundstage depth to be an interesting aural perception.
Mono recordings from the ‘30s and ‘40s are recordings where I do not “see” a tall, wide, expansive, immaculately separated combination of elements, but a narrow, short, yet wonderfully deep “tunnel” where I can “see” into a deep background.
Just my personal experience.
I find many modern recordings are very “shallow.” Right up front and dry, almost like a pencil sketch on paper instead of a deep, 3-D experience.
Something antithetical to such a presentation might be, say, Rudy Van Gelder recordings from the ‘50s or ‘60s, or September of My Years by Frank Sinatra. A far more palpable sense of physical space between the various individual sonic elements and a far more dynamic and expansive overall presentation in terms of depth, width, and height,