The thing is though that the depth is contracted disproportionally much more than width and height, which results in a non-linear transformation of perceived dimensions. This causes lines to bend. At 47mm straight lines aren’t bent no matter the distance from whatever there is in the picture. At shorter lengths there are always regions in your photo which are distorted in this way. You can’t fix that by changing your position. The only thing you’ll do is change what object is bent and in so doing maybe make it less obvious.
I have a 28mm lens with a symmetrical design that shows no distortion
I agree that, in general, wide angle lenses are harder to design in term of distortion control, but it's not a god given rule that all lenses wider than 50mm have to show distortion
That's lens distortion, and has nothing to do with depth. Phones will correct it in software automatically, and Lightroom etc can also do it for your DSLR lenses.
It's not usually a concern until you get to <20mm, and especially not if you're going to crop the center of the picture to mimic a 50mm perspective.
