I’m a sound engineer and I know full well that they don’t, I don’t buy into audiophile foo, but the notion that all DACs and digital sources sound the same is just BS, some people wedge “well designed” or “properly designed” in there, but that must mean that the vast majority of stuff out there, even massively popular stuff that people love, is not well/properly designed. The reality is, that almost nothing is perfect, but rather the best compromise the designer could come up with given the budget they had to work with, and factoring in what is most important to him/her.
Digital comes in different flavours, just like analog, and you pick what you like... it’s funny that many of those that claim certain products are totally transparent, are the same people who move said product on when a new flavour of the month “totally transparent” product comes along. I’m not pointing the finger at anyone in particular here, it’s something I’ve noticed across the industry... meanwhile, I’m listening to a 20 year old CDP right now, it was absolutely epic when it was new, and it still is now.