It is worth questioning how you define "work". I may only sit in my chair coding for a couple hours a day. (And a couple more on meetings and documentation.) But I'm thinking about the problems while I am doing chores, going for a walk, etc. Then when I do sit down to code, it comes to fruition quickly. If I were to spend 8 hours in a chair staring at the screen, I'd "work" more, but I'd accomplish less.

This is why I am such a proponent of remote work, at least for coders - it allows us to spend more time doing what is truly the core of our job: thinking, and less time just sitting in a chair typing out those thoughts into the proper syntax.