I would agree with you, but since this will be my word vs your word, I will quote:
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That is almost what I would have said, except that there is a whole lot more to it. It all boils down to knowing your electronics.
In layman's terms, your setup would need to be in harmony, except that we have loss, noise, etc. Though all this can be mitigated or negligible.
Today we have digital music tracks that are mastered to adhere to things like Apple's Adaptive Audio. In theory, the audio will always be at its best given the hardware used, but it is not up to standard as "audiophiles" would point out.
Personally, I consider the more 'vintage' hardware as being "audiophile" grade, and there are modernised vintage systems. New buyers like wireless hardware, and then we start to look at codecs and bitrate technologies. Then there is DSP, that no one with wireless hardware can escape. This said, some DSP applications are good, and can make 'cheap' hardware sound premium, and in high-end applications it can really give wires where there is none.
I'm no audiophile, but I do know audio, well, the engineering. It is a hobby.
There is a reason why tapes and vinyl are making a comeback, even CD, and the Walkman is coming back. Simply because it is less diluted, and people should thank IEMs.
Look, your remark isn't wrong, it is only that you can come very close to it, but then you have tracks that throws that balance and you would be pressed to EQ.
In the end, your outputs play the larger role, impedance and all that. Pairing audio hardware is like having a marriage, one that will divorce at some point in time.