Pesticides are a problem, but almost always secondary to wholesale habitat destruction in order to make farmland (mostly to grow feed for cattle in this country) and suburbs. Pesticides are just a tool to make those new "more profitable" landscapes.
Modern commercial farming leaves no room for nature, and suburbans folks seem to think ants and spiders shouldn't exist. Turns out the same things that kill "pests" and "weeds" generally make it tough for the cute things we like.
We're reshaping the world, often in ignorance on how much we actually depend on these ecosystems we are destroying.