Actually apocalypse did come-- in the last century there was mass starvation in Russia, China, Ukraine, Ethiopia, North Korea and more....literally tens of millions of people starved to death within living memory. Plus, large scale factory farming is not necessarily the economically optimal way to farm. We can't know because the US and other governments MASSIVELY subsidize factory farming...the market is extraordinarily distorted. Even further, there are questionable regulatory burdens foisted on small farming operations.
Lots of civilisations have collapsed throughout all of history. Millions of people have starved to death as a result. What makes you think we're somehow immune?
Sheer arrogance makes these people think they are immune.
Plenty of people are starving today even probably less than a mile away from anyone eating well.
The system does not serve everyone equally and ultimately we may all suffer one day.
People starving today aren't doing so because there's not enough food nor because people don't know how to grow it.
Farming today has to be a large scale, highly studied and high-yielding enterprise. There's lots of room for improvement, but very little benefit to it on a microscopic scale (put seeds in ground, water, hope they grow).