Who needs insecticides?

Just saw this:
More Flowers, More Food, More Bees, Fewer Pests. Can It Get Any Better?

Could cornflowers and poppies take the place of pesticides? That’s what researchers are proposing in a new study on wheat fields. By planting strips of wildflowers alongside the crops, the scientists found that they could encourage the presence of helpful bugs that eat pests.

They found a 2.5–10% increase in yield—with no pesticides! Increase, not just remaining stable...so why aren't we doing it?