Partly proves the point of the OP: cutting out the forests and draining the swamps led to soil erosion, massive floods, and loss of biodiversity.
I'm not saying it had no reason or benefit, obviously it was for economic reasons (extra land for agriculture and human settlements), just that it is not something that should "obviously" be done.
GPs point makes it sound as though the destructive parts were unintended and a surprise. They often weren’t, and they very rarely are these days when it comes to “landscaping” (sorry if that’s the incorrect terminology in English).
We know perfectly well how to alter the land we live on. At least in the EU we’ve been turning fields into swamps or forests and back again for various reasons since we industrialised farming. Basically all of the effects are known. While we can agree or disagree with a lot of the choices that are made in terms of economic growth, it’s not like what happens is surprising or unintended.
I'm not saying it had no reason or benefit, obviously it was for economic reasons (extra land for agriculture and human settlements), just that it is not something that should "obviously" be done.