Greenhouses are a tiny sliver of overall food production. The rest of agriculture is heavily biased toward the energy density of fossil fuel, particularly nat gas and diesel. The innovation required to move away from the actual energy problem in agriculture is much greater than a bit of creativity
Moving away from these kinds of farming methods is really not as hard as people suppose. For a start, composting food waste would produce a carbon neutral source of fertiliser that would cover fairly large amounts of domestic need. Measures like these are really not hard. There's a glut of alternatives available, government simply does nothing to aid in the transition.
For starters, a commercial scale composting operation needs inputs from various sources in order to achieve NPK balance - not just food waste. Therefore, the complexity increases by an order of magnitude as we have to orchestrate the logistics of food waste, manure, wood chips, and more.
Second is that compost is not even close to ammonia-based fertilizer in terms of elemental nitrogen, which is critical for our most calorie dense crops. Places like the Rodale Institue are not at all intellectually honest about organic production yields. Their systems fall apart at the global population level.
It is a fact that if we were to shift all-organic farming that we would need MORE land, and MORE people to create the same amount of food. That's the opposite of our current goal which is to create more food with less land and less people.
Third, the application of compost would actually increase soil compaction due to larger, heavier equipment required. It just so happens that these large equipment (tractors included) are not yet able to run on electricity. There are some electric tractors, yes, but nothing with the power equivalent to modern combines.
Fourth, is the bias toward energy density that I hinted at in the third point. But it isn't just tractors. Many farm operations are unable to electrify due to their proximity to the grid and the energy draw. I'm talking about grain storage and refinery, and many others.
These are all problems that could be solved with innovation. But to your point, it is probably HARDER than many people suppose. Definitely harder than you are making it out to be. Food systems are incredibly complicated. It is also incredibly optimized, and advocating for a massive shift comes with the intellectual responsibility of addressing this complexity and coming up with a solution that can compete with the status quo.
To your final point, the government is doing a lot to aid in the transition actually. Not sure where you are from, but the USDA is now offering more grant programs than ever before to address all of the above.
