I think the casual reader will get the wrong impression of the term “sub optimal move” as if people are sacking pieces just to move off of well-traveled paths. The moves being discussed here are often imperceptibly sub optimal, just variations that came out a few decimal points inferior to another move.

There’s very seldom a single, obvious move that makes sense. The level of chaos in chess is still sufficiently high to make it an interesting game, even when you study all the available opening theory.