Happily, this is one problem we can totally solve. Humans can make soil MUCH faster than nature typically does. A lazy human can pile greens and browns, walk away, and 6-12 months later there will be fresh hummus there. A diligent human can shove the same stuff in a spinner and produce a cubic yard of humus in two weeks.
To function on a large scale, one simply collects the stall contents of livestock for composting or spreading directly on fields in the fall. Conveniently it comes out the right proportion of ingredients. Another good option is to plant a cover crop, let grazers out to eat it, and they will naturally spread fertilizer. Till, wait for breakdown, and go on with your planting.
Also worth mentioning, we have multiple modes of growing food that don't wipe out topsoil. Some like hugelkultur even make it while growing food. With a food forest you don't even till the soil.
Farmers are upset about soil loss? Go make some more, you lazy bastards!