It's not (solely) random imperfections - a good drum groove will have intentional specific deviations from the "theoretically exact" (bad) beat timing, no matte

It's not (solely) random imperfections - a good drum groove will have intentional specific deviations from the "theoretically exact" (bad) beat timing, no matter if done by a human or a properly engineered digital track. There is a difference between the crude musical notation and how it's actually meant to be played - a notation showing 4 quarter notes in a 4/4 beat does not imply that the correct way to play them is to literally have 4 identical notes with idential gaps; even without any explicit extra notation (which indicates significant changes) there is an implied understanding that there should be a variation in velocity (and, for a skilled practicioner, not a random one, but placing slight emphasis as required) and a variation in timing (again, for a skilled player not random but e.g. depending on the music genre a slight shuffle or an intentional shift of one beat); this variation is not a flaw of imperfect execution, but required to properly play the music as intended.