I guess the difference between the farm and business is that the former doesn't have non productive work. It is amazing how much energy I lose in meetings or similar.
Agricultural lifestyles support an order of magnitude more people per unit land, and therefore are more fit, even if they're "worse" in subjective terms.
Also, the "mistake" didn't happen immediately. It's not like hunter-gatherer nomads immediately decided, "yep, we're doing this farming thing" and started domesticating crops and animals. It happened gradually, over thousands of years, with various intermediate shades where a group would do some of both. Over time, human societies got to a point where abandoning agriculture would be impossible, while hunting and foraging became more discretionary.
What on earth do you think this proves?
On the flipside, I'm sure in practise it is a net time waster.
Use https://www.rescuetime.com/ and you can track your time spent working and easily block distractions so you can focus.