While on the level of an individual farmer that makes sense, what about the whole of society? From what I understand, in archeology driving marginal land out o

While on the level of an individual farmer that makes sense, what about the whole of society? From what I understand, in archeology driving marginal land out of cultivation is one of the prime indicators of a civilization in terminal decline. Advanced civilizations tend to rely on irrational productivity quite a bit, hence things like the post-COVID labor shortage.