The reason this is not common as it’s not really needed.
No one has any idea if this is needed or not because end users never get to measure it themselves. The argument here is really that unless it's blatantly obvious to the ear we should not care. To those people I ask: Do you even buy high end equipment?
I've read a number of reviews, and experienced enough variance in performance of sources to know that this is not the case. Having some sort of Green/yellow/red indicator about signal quality and noise I think would be helpful. For instance, there are a number of reclockers and signal cleaners on the market. Wouldn't it be nice if our DACs could indicate directly if a particular source might benefit from it?
Like, green on CD player, green on streamer, but woah, that AppleTV signal is a mess.
So pick your place. Bits are bits and unless the signal drops out I don't care, or I care about signal quality and would like to know if I'm missing something important.
Best,
E