In my experience, the source dictates a big portion of audio system’s sound.
Interesting viewpoint.
I prefer to compare components in my system because it offers a familiar baseline.
I can’t make heads or tails of systems’ sound from YouTube videos, and I definitely can’t tell what a particular component sounds like. I don’t have that skill.
I tend to think a system’s sound is holistic, although I ascribe the largest influence to speaker/amplifier pairing.