When I first got a hold of bootleg multitracks in the late 00's (before the Rock Band stems proliferated) I was amazed at how unsteady so many of those individual tracks are. Didn't matter which band it was....The Beatles, Zeppelin, Hendrix, Queen, everybody. But then when everyone played together, it sounds so good and "perfect" (or at least, a natural perfect). Definitely a case of whole greater than sum.
It made me feel better as to why I thought my own recordings were substandard. Well, isolated drums tend to sound slightly janky in parts too.