I have a lot of respect and even awe for modern agriculture. It's incredible what we've done.
> The trade-off in abandoning these practices almost always involves sacrificing yields and the mechanization of labor.
The problem (that cannot be escaped) is longevity. Any system of agriculture that does not increase over time soil fertility and volume/mass is doomed.
Systems of agriculture that deplete [various measures of biological health] over time are akin to mining. Once the underlying resources are exhausted the story ends (the resources in question could be water, or biodiversity, or climate stability, etc...)
Even if we compensate with technology, we are substituting our managed system for a automatic system that has been (meta-)stable for billions of years. We should proceed carefully.
The billions of people who owe their lives to the Haber-Bosch process (and other innovations) may come to rue it if we crash due to environmental destruction. By some scientific estimates this is the decade when our biomass and the biomass of our agriculture outweighs naturally occurring biomass. For better or worse the world has become our farm.
That's why Gabe Brown (et. al.) seems so important to me: he is integrating modern practices with new (scientifically-validated) regenerative practices and his farm is both profitable and healthier year after year.