Thank you for this. It is absolutely frustrating to hear so many comments that isolate one factor to the exclusions of others. Profit is income minus expenses, so if you spend very very little, you can make a profit with little revenue. Revenue is a function of price per unit times yield,so if your prices are comparatively high your revenue is low because your yield is very low.
Low yield has important and detrimental environmental consequences in that far, far more land is being used to feed the same number of people. The loss of natural habitats is an important negative consequence of our need to produce food, so efficient land use is very important to protect biological diversity.
Now, land use efficiency has a number of factors to consider. The use of the crop is one, such as are we growing crops to feed animals that we eat? This is always inefficient from slightly (say, chicken) to massively (such as beef). So if you are championing permaculture to solve the ills of chemical pesticides and mineral salt fertilizers, you really should focus on eating crickets and plants, as this would have a far greater impact.
On the matter of chemical versus alternative pest controls, this is again often subject to selective comparisons. For instance, there if insects are ravaging your grapes you could spray a chemical pesticide that selectively targets insects with piercing-sucking mouthparts that will plug their feeding tube and stop damage, eventually killing the insect, or you could spray kaolin clay and create a deterrent that may suppress enough damage to protect your crop. Sounds ideal, right? The clay has no detrimental effect on insects, is completely non-toxic, etc. However the chemical insecticide is applied at say 500ml per hectare, where as the kaolin requires say 25 kg per hectare and requires two sprays to establish adequate coverage, and needs to be reapplied after every rain, while the insecticide is systemic and residual, persisting inside the tissue of the plant for a few weeks before being metabolized. That means the clay is a lot more water and fuel intensive, increasing the footprint of your operation. The 500ml of insecticide costs say $30, while the kaolin costs around $160 for the first application and $80 each time it rains. Before you assume the evil chemical giants are manipulating the market to favor of their product, remember that that clay was 25kg (as compared to 500g) -- that's a LOT more gas to transport from the quarry to your farm. So when you look at the whole picture, that ideal seemingly zero-impact alternative actually greatly increases water use, gasoline use, CO2 emissions, the amount of farmland required for a similar yield, and ultimately raises food prices.
My point is that while the way we grow our food has to change, the answers are complex. Returning to "older ways" by rejecting scientific advances will not help us unless we are also prepared to accept a vastly lower population and the human misery that would entail. If you really want to help, get involved in the doing of agriculture, either in the growing, researching, or distribution of food and help create real answers. If that is not in the cards, then look at how you can change your use of food to create the change you want to see. Stop eating meat, eat insects. Make sure you don't waste food. Stop driving to the store and get your groceries delivered (a full half of CO2 emissions comes from getting the groceries home from the store and delivery reduces that significantly).
Most importantly, do not champion solutions as a cure-all, or denounce methods as deadly mistakes without putting in the time and effort to justify your position. Until then participate, learn, push the values of lower impact and sustainability, but trust that there are many many people all through the agricultural sector that are of the same mind and working hard to advance those values.