Environment matters a lot. It's not "travel for 1 week" that will cure the mind, but rather, removing the slave labor you don't enjoy from the box entirely.
The author seems to miss this critical point (that many people are unhappy with their day job because it's basically debt/wage slavery without ownership).
I haven't done "slave labor" for more than 20 years, having initially imagined I was rich enough to retire at 32 (that turned out to be wrong), then later converting an open-source passion project into a very comfortable middle class living. No boss, no rules, no schedule, just lots of people who love what I do and that includes me.
However ... the Box of Daily Experience is still a feature of my life too.
There are plenty of days when I reflect on how it was just another day, same old same old, completely predictable. Granted, I don't have to put up with the BS of a regular job, which eliminates one aspect of the Box of Daily Reality for me. But then again, I work (mostly alone) from home, and so my days involve very little physical interaction with anyone. Equivalent to the suffering of slave labor? Probably not, but just a different element of my particular Box of Daily Experience.