This thread is an excellent example of ALL 10 cognitive errors nicely listed here: https://aha.zone/10-cognitive-thinking-errors/
There is no logical reason to argue somebody's private decision of purchasing audio solution, observing positive/negative results in THEIR system, and deciding to keep/sell them in spite of very expensive ticket prices, even if that improvement does not work in another system. To illustrate my point I would propose an equivalent question: Can you deny the existence of the placebo/nocebo effects because it never happened to you? Not to mention that even if you believe in them, you can never really claim it without a double-blind case study.
I didn't believe cabling impact on the audio path at first (a long time ago) and experience it everyday now, especially when some can be detected only on specific tracks.
Let's please have some respect for other people. Arguing audio as it would be a political ideology completely disregarding rights to the individual rights/opinions is very 2022 but, simply, also very ignorant.