I asked for a definition. You answered with more undefined terms. What does "top of the stack" mean? Is it the total number of hours worked? How do you establish who is at the top, and why is it important to you?
Not, why is it important to the company, but why do you personally want to work an additional 4 hours per day to get to the top of this stack?
Once you've answered that, you should be aware that the many studies of learning say there's only about 4 hours of real skills acquisition or creative work possible per day, for the long term. And that past 8 hours your productivity decreases, and people start going to work so the body is present, but they end up doing other things instead, from paying bills to playing videogames to commenting on HN.
Things they could easily do at home. While videogames and HN are fun, what of those who find cycling, dancing, or hanging out at the bar more fun? Why should the company control your free time?
And you don't have a problem with that?
Also, see https://en.wikipedia.org/wiki/Vitality_curve and the companies (Microsoft, Adobe, others) which have abandoned stack rancking.