If you take a worker who operates efficiently to increase their own personal time and increase their workload without providing some offsetting "carrot." The worker has two rational responses in a liquid employment market:
1) Reduce their efficiency to median company levels and only use their efficiency "secretly." Congratulations, you've broken their spirit!
2) Find another job because they're an above average employee.
My point is just that there's no real incentive to work more efficiently (eg by automating or by smartly planning ahead) and my employer is happy as long as I stay ahead of milestones and generally work well, and its somewhat demoralising knowing that there's an infinite stream of work and no matter how hard I push myself, this doesn't get smaller, I don't get to leave earlier etc. This can be especially frustrating when other people on my team who are being compensated roughly the same as me are not pushing as hard. Why should I?
(In case someone who knows me is reading: this isn't actually the case, I'm asking hypothetically for the sake of this discussion)
*assuming you're being paid a decent wage and we're not talking about work being done to extraordinarily tight deadlines for no reason, in unusually poor working conditions, or something like that.