One of the factors is amortization of capital….short seasons (In northern climates) means narrow windows to get the next crop in the ground and therefore less ability to amortize a major investment. In natural forests in western Canada there is also a lot of variability a machine has to contend with. Of course it depends if you are planting seed or seedlings mechanically.
Each jurisdiction in the world has unique challenges but perhaps a common one is the “we’ve always done it this way” attitude one has to break through to establish new paradigms.