Define “easily”.
Seriously, if you ever dealt with land in your life, you would know agriculture is anything but “easy”. It only exists in today’s shape and form thanks to fossil fuels, massive government incentives and cost externalities.
OK fine it's hard we still have to do it though you can't just throw up your hands and say "eugenics time!"
It still seems pretty clear to me that the problem is resource overconsumption, not simple overpopulation. Let's address that first bit first then see where we are.
The problem is you can’t discuss consumption without addressing the population. The current economic model simply pushes the rest of world to consume at the unsustainable levels of a North American or European citizen. One of those will have to give.
When you hit "the world can't support everyone living the way we live" the problem is with the way we live, not with everyone living.
We can easily provide healthy nutritious food to everyone and many many more. Just not in the form that we are currently choosing for ourselves.