There are surely a lot of pretenders and rich posers, perhaps more than we think, but this is quite a sweeping statement, which is effectively untrue.
There are differences between compressed and uncompressed quality ( with exceptions of zips and similar, but that's another matter, it isn't a permanent compressions, merely different way of packing things). You just have to train your ears or eyes to distinguish the differences.
Trained, decent violinist will surely provide more precise feedback and would be able to pick up nuances and issues amateur won't even notice.
Professional rally driver is able to drive car safer at twice the speed than majority of us could.
Same with whiskey connoisseurs. To me, an expensive whiskey is a waste, because I can't appreciate and pick up all the sublime differences ( nor I am ready to pay stupid money for it) but saying that cheap blend and good single malt are the same, is just wrong and ignorant....