The Lord of the Rings is considered a fantasy because the trees win the battle against industrialization.

Thomas Malthus was an English philosopher and economist who thought that because food growth grew at a slower rate than population growth, catastrophic events such as famines and plagues were always needed to "re-balance" the population. While he didn't advocate for going back to nature like Treebeard (and to a lesser extent Tolkien, although it was more nostalgia than a real policy, as he understood you can't go back), it's clear that trying to reverse technological progress, particularly in farming, would kill of millions of people in a kind of Malthusian catastrophe.
Malthus was wrong, by the way, precisely because the industrialization of farming has the exact opposite effect that he was describing (food production goes up at a much faster rate than population). Saruman's industrialization is the cure to the perpetual famines that humanity used to suffer.