There are plenty of articles that demonstrate that the quality of digital cables matter. Be it - jitter, current, voltage, .... its not just 1s and 0s. Just as ground plane has a tremendous effect on cable signal. Saying cables don't matter is like saying that the quality of your tires on your car don't matter. Everything matters. Yes the power source matters, but minimizing effects of AC on equipment involved matters. AC is full of noise that can and does have a causal effect on audio and video reproduction.
Again - saying cables don't matter is very short sighted - mainly from those that either can't afford the cables OR are not astute enough to notice the difference because they don't have quality audio gear, or are deaf, hard of hearing, or just flat out refuse to accept that cables - just like everything else - matters.
Higher quality ingredients and higher quality product development and manufacturing - regardless of product space -- will yield higher quality results.
To suggest otherwise is naïve at best.
" Listen and you will see. "