You are reading into what I wrote what you want to think, not what I said.
Imagine being in a room, the left wall is one shade of blue. The right wall is a different shade of blue. You can see the shades and clearly identify them as different. I now lower the lights. It will get harder and harder for you to tell the two walls are different until at some point you cannot tell that the walls are two different shades. If I keep lowering the light, at some point you will not even be able to clearly identify walls. I could have started with red and green walls and at some point you will not be able to tell they are different colours.
Why do you readily accept a very finite and limiting range for your sight, but insist on an infinite range for your hearing?
I acknowledge DACs can sound different and I even discussed preference in filters. How can you interpret that as black and white and not seeing greys? I accept, as it is reasonable, that just like there is finite range for our sight, there is finite range for our hearing. For that reasonable reason, I am skeptical that it takes a large sum of money, to make a DAC that exceeds the range of our hearing. If it does, DAC vendors are doing a poor job of proving their case.
What I don't understand is why some are so attached to this idea that to get the basic function right, it must take a lot of money? Filters, tube output stages, and I am sure many more ways exist to create a differentiated sound. Attractive cases, nice displays, added functionality. So many ways to differentiate your product. Why the need to insist getting the basics right is expensive?