You should put in the effort because your effort directly affects the people around you. Stop caring about management and instead care about your coworkers
Do a crappy job loading a drivers truck and you’re making his entire day difficult, and they already have a very tough job as it is, a lot tougher than people realize. Work at a safe pace, Completley zone out management and don’t care about their numbers, but still try and do a good job, if only for the reason you don’t make someone else’s day worse