Frankly, yes, they do fix themselves. You'd be utterly shocked at what landscapes look like if we leave them. Having been part of forest regeneration efforts across the UK for the past 8 years - from southern heathlands to rocky Welsh and Scottish outcrops, good for "nothing but sheep" - I can say with all certainty that every part of the country except the most extreme alpine regions is suitable for reforestation or some form of plantation dense rewilding, mooring, wild flower meadow, etcetera. The same can be said of much of Canada and America, with my peers over there having the same results when grazing stops. Hell, the Mongolian steppes are turning to results of goat herding, and the Gobi desert is though to have been cause by the same.
In the UK for example, people are completely ignorant to how the place looked before we levelled it for grazing, viewing the 70% ecologically barren agricultural land (of which 80% of that is used for grazing or agriculture to feed cattle) as the norm and the 2.5% old growth forest as a more novelty, and something strangely "unique to that area". The country was 60-80% temperate rainforest before human habitation, depending on what research you go by.
Maybe we should blast to level it, and make new soil then?
Around here, Quebec Canada, few cattle are grain fed, and the land they graze on is rocky, hilly, non crop land.
But, even more importantly, is that there is no food shortage. None. Zero. Nada.
In fact, all around the world, Canada, Europe, farmers are paid not to farm.
I detest it when people try to obtain goals, by using false narratives.