Even with mocap stuff, people outside the industry just assume you shoot something and it just works. The amount of cleanup, and polish required beyond that and the hours that go into it are rarely talked about. End result is the actor's performance + hours of an artist's painstaking labour.

I usually only use the COG for up and downs as the character walks or accents when they're talking. But, this is largely because of how the rigs I've worked on were setup tbf. Animating the COG, especially rotation, would just throw everything out of wack