That's exactly why the number of farmers keeps reducing under capitalism. In socialism, you can get to democratically decide how much people are paid depending on the actual needs of the economy.
No, mate, I'm obviously not suggesting a return to feudalism. I'm suggesting that if humanity needs more people allocated in agriculture, it should allocate more people in agriculture.
Allocate doesn't have to be through violence, it can be through incentive. If farmers made twice as much as stock traders and worked 30h a week there would be plenty more.
But what if you can't find enough people to do farm work? A lot of people work on farms now because they don't have much of a choice. And if you could do easier work but be paid the same as you would on a farm, why not take advantage of that?
With modern farming, 10% of the people can now produce enough food for everyone. And if everyone had equal income instead of the top 1% syphoning off half the wealth, we could globally support a middle class lifestyle by everyone working 20 hours a week, the same amount that hunters and gatherers “worked”.