Does Your System Sound Like the Real Thing?

your system is indistinguishable from live performances

No way.
One system might fool you -- but that's a musicality issue. The other is higher rez -- but that's "true to SOURCE" i.e. the recording, NOT the musical event.

IMO that's all we can achieve -- and it's not bad after all: either a "musical" sound reproduction OR a "true to source" reproduction. Whatever tickles our collective fancy.

So,

If the answer is no, do you even think it's possible

Of course not.
Not only are recording techniques & storage media a limitation; the speakers & spkrs-room interaction are even more so, as Ohlala notes above.

BTW, and similarly, a portrait is NOT the actual person, is it? It's an artist's interpretation and rendition of that person. (I'm putting sound reproduction on a high pedestal here:))
Cheers

Why should a cable have to make such a significant difference and cost so much to boot

Have experienced this and, as a diyer, it's VERY frustrating!

For the 1st part, obviously the transfer function and noise reflection/rejection -- why/how? I don't really know, wish an RF person could chip in here...

For the second part (the cost), well... two points: a) small proprietary wire runs are VERY expensive
b) when a cable geometry WORKS WELL (remember, a rca cable is asymmetric, so more complicated) one just indexes the prices vs other outrageously priced products.

I'm trying to work out the Valhalla. I still have a way to go...:)