I doubt the average mlb pitcher can "command" his changeup. As far as I understand it, command means "placement" and generally speaking, not very many mlb pitchers can "place" their changeup.
There are times (few of course) when my son's changeup is working good enough to be his out pitch in games. Its just so difficult to be consistant with it. Son doesnt throw hard enough yet (mid 80's) to have an overpowering fastball and thus why he has worked hard on his breaking ball. He has really refined his breaking ball to be his go to out pitch. Years ago I was of the philosophy that developing the breaking ball sooner rather than later would eventually lead to lower pitch counts and thus less "overuse". Our hs team keeps stats and guess what? Last year he led the team in least pitches per inning at right around 15. I did some research and found that that number was actually slightly below mlb average (16). Our team average for pitches per inning is around 17. If my math is correct, my son pitched 200 less pitches last season compared with team average because he has worked hard on commanding 2 pitches (fastball, breaking ball). Some may argue that the breaking ball is dangerous on young arms, and for some it may be, but saving son from throwing 200 extra pitches in a 4 month span, in my opinion, outweighs that risk because I am limiting the number 1 factor of "overuse". Pretty much every pitcher overuses their arm at some point in a game, season etc. Pitch counts came into being to thus limit overuse.
That all said, my son is really focusing this year on the elusive changeup. His philosophy, his goal is to lower pitch counts per inning which we both believe is the ultimate factor that leads to overuse.