> Native Americans would have used up their forests

They already had used up a large fraction of North America’s forests. Killing off over 90% of the population + 200 years of growth before Europeans showed up made people underestimate just how young most of NA’s forests were.

Similarly native agriculture was massively underestimated because large settlements were killed off first when the plagues hit. Ever wonder why if Corn and potatoes etc were as native crops, why native Americans are depicted as hunter gatherers? Hunter gatherers has slightly better protection from disease. They represented a small share of the population in 1492 but by the 1700’s they where the shattered remnants wandering through graveyards of dead civilizations.