There are people who are in this hobby and claim that there are not differnces between cables, or that digital transports sounds the same or that diy dacs or speakers sound good or better than hi end products. Perhaps I would argue with them, if I had extra time to spend on unknown people and unimportant subjects.
On the other hand, there are people who are not in this hobby and to whom any properly configurated hi fi system may sound almost the same and who are not burdened by its imanent idiosyncracy.
It would be wise if every such statement should be taken within its context and with proper understanding of its origin.
On the other hand, op has raised some interesting questions, perhaps even unintentionally. Some food for the thoughts...
Does hi fi have meaning beyond listening of unamplified music (other than classical, jazz or similar)
Does anybody really believe that hi fi reproduction can sound like a 'real thing'?(except for the tone and timbre of instruments)...Stereo does not exist in the nature...(there are excellent mono systems, I know)
Hi fi is all about creation of illusion of 'live event' and no matter how big is your room, I doubt that anyone can fit in a symphonic orchestra...Somebody even wrote that his reproduction is even more real than the live event...which is fine if you are fan of hyperrelism...but, some might call such way of expression as artificial, with every right...
Naming hi fi as a tool which will help as hear the recordings as they were made is another myth. Nobody, except the mastering engineers knows how something sounded before its been worked on. We can only compare the recordings with our imaginary references, that were made on live events or perhaps by listening different gear.
In any case, the op does not deserve the personal attacks. Hi fi should be fun and enterteiment, a hobby (no matter how pointless or expensive it might be) and not the extension of someone's ego...