Hardly anything is cleaner post industrial revolution. Not only are there more people but we use more resources per person and produce more waste products. That shouldn't be surprising to anyone.
There are exceptions though, sewers and sewage treatment have been a great invention. And big cities aren't drowning in horse shit which was a major issue in London and New York at the turn of the twentieth century.
Because wretched nigh on universal poverty, above 50% infant mortality, famine every 20 years killing perhaps a quarter of the pain, endless toil, all these things are bad. Given the choice between living like the average peasant in 1800 and maintaining something like our current first world standard of living and health while so destroying the environment that the first planet we need to terraform is Earth people will choose the latter. Most of the world’s population was peasants in 1900. No one had antibiotics. Air conditioning was practically unknown.
The state of nature is hellish and people will absolutely pave everything while breathing air that tastes like an ashtray to avoid it.
There are exceptions though, sewers and sewage treatment have been a great invention. And big cities aren't drowning in horse shit which was a major issue in London and New York at the turn of the twentieth century.