(Feudal Japan took this literally. A Masu is enough rice to feed a man for a day. A Koku is enough to feed a man for a year. Accountants and tax assessors did paperwork doing math in those units. Anyway...)
The $15/hr minimum wage argument cracks when looked at under the conditions of modern retail, but it really falls apart when it's looked at in agriculture. Bringing in a crop is a really hard, labor and skull sweat intensive, year-long gamble that you'll pull everything in at harvest to pay off everything that's been hanging over you all year. And mechanization can only do so much. Especially at harvest time, it relies on seasonal labor willing to work for peanuts. Otherwise, the gamble doesn't pay off and the farm is lost.
Add in globalization, where you're not just competing with the farm down the road but the one across the globe... it gets even moreso.
That's the big hurdle that needs to be jumped to actually fix the problem instead of just kicking the can down the road.