Yes they used to do forestry like that in Northern Europe. They realised the methods described by the OP are more sustainable and more reliable (e.g. diseases will wipe out monocultures).
I agree with it being better for the world in a lot of ways. And I would like to see it change, but it isn't likely to, at least not for a really long time.
P.S. As for mono culture timber, there is a reason almost no one in the US knows what a curant is. They (are/were) illegal in the US, because they are for a vector for a fungus that can wipe out timber pines.
P.S. As for mono culture timber, there is a reason almost no one in the US knows what a curant is. They (are/were) illegal in the US, because they are for a vector for a fungus that can wipe out timber pines.