The destruction of agriculture or the minimum sustainable ag, was a series of "bright ideas" that were never properly tested and failed epically.
First, The commodity market. The commodity market controls almost every aspect of food processing and distribution (In Canada looked to the ultra wealthy buddy of Trudeau, Galen Weston). One of the biggest issues with this is farmers getting lower and lower prices for their raw products (live animals and/or crop). You can't afford to earn $2.50 per pound of cattle if your expenses cost you $4 per pound of cattle. The farmer doesn't even cover operating expenses, let alone make a profit.
Next, the "get bigger or get out" mentality is another uber failure. Earl Butts (from the Nixon administration) said one of the dumbest things to farmers in the 1970s when he told them to "plant fence row to fence row". Along with this, farmers have been buying larger and more sophisticated machinery for haying, plowing, tillage, planting, packing, hauling, combining, etc. I personally know several cash croppers who are borderline being bankrupted or have been who purchased $1 million plus heavy machinery and try to farm thousands of acres. They hope the price of whatever crop they grow stays reasonable. Add to this the extreme time consumption and you easily see why cash croppers will tend to ditch cattle and other livestock. Also factor in the enormous fuel and maintenance bills. Going bigger for the hope of making a few more dollars doesn't work without a plan.
Chemical farming vs Biological farming. Around the time of WW2, with surplus of chemicals for available in industries for blowing people up, scientist with little scope for full impact encouraged farmers to use plenty of N, P and K fertilizer. Yes, it fools us into thinking its progress because plants grow huge, dark green and tall. Their are many problems with this. The plant needs to take nutrients up into a balanced and slow manner to avoid things like nitrate poisoning (among many other issues). Add to that poor practices like plowing and all that expensive fertilizer ends up getting washed away into forest, swamps and waterways (BAD bad bad). Biological farming using the six soil health principles that Gabe Brown promotes (Minimal soil disturbance, keep a living root in the soil at all times, Animal impact, cover the soils at all times, natural biodiversity and farm within your context) is biology based farming. Many, many farmers are seeing huge success transitioning to some or all of these principles. Chemical farming is just giving away more of your money for an illusionary gains.
Plowing, tilling, disc ripping, etc. are all heavy forms of soil disturbance. They create an illusion of relieving compaction and bringing up lower minerals. Both of these paradigms are false and very outdated. The soil is a living ecosystem of bacteria, fungi, insects, worms, nematodes, plants, animals, spiders, etc, etc. Its the many bacteria and fungi in the soil that makes nutrients available. Its things like glomalin (liquid plant carbon exudates) that help form a natural nutrient dense binding agent in the soil. It is plants with powerful tap roots like daikon radish, turnips, dandelion, burdock, etc that aleviate soil compaction. Mechanical disturbance destroys soil structure and rapidly oxidizes the soil nutrients. Forcing farmers to use more chemical fertilizers. Putting more cash into someone else's pocket. Its a terrible treadmill.
Next, we move more and more of the human population into urban environments and create that distance from farming. Next thing you have is hatred and at the very least unsympathetic feelings towards farmers for many, many issues.
In our so called civilized western societies, Farmers are down right crazy to keep going. I am, so good to go (most soldiers are a little or a whole lot cray). In all seriousness, I will not play the commodity market game and I design my farm ecosystem on the six soil health principles. We minimize fossil fuel use. and encourage our customers to eat lots of meat, especially ruminants. Personally, my wife and I are 90-95% carnivore November to May and then more plaeo based rest of the year (my mother cooks many of our meals in the summer, so veggies are added back in).