I know a lot of folks do not care for this guy or his musings, but he has a point if you are digital only. https://youtu.be/81RQLo0tLHE?si=t9BKS9t34O0bESV2
Dealer OCD Mike peddles a 22k Playback Designs DAC that voids all preamps apparently on most of his videos. This video is no surprise. It is very doubtful that the dude's dac does endless miracles with every amp on earth..
It is not that much a mystery that amp manufacturers will design a pristine sounding poweramp and pretty much try to lock you into a pristine sounding $$$$ preamp they specifically designed for it (atleast in the high end). All the DACs and the preamps from other manufacturers can sound less optimal thereafter with that poweramp (Not always though and there are enough exceptions, of course)..