It's partly due to mowing alongside highways and medians. ... fewer tall grasses means drastically fewer bugs This is way too general: in some countries and al

It's partly due to mowing alongside highways and medians. ... fewer tall grasses means drastically fewer bugs This is way too general: in some countries and alongside specific highways, the state of grasslands is actually really good. Like: good enough to grow rare orchids and having >10 or >20 plant species/square meter. Because of correct mowing regimes for that vegetation type. It also lacks nuance because as explained in another comment already: not mowing at all can make things worse. Which brings us to the tall grasses: meadows featuring a lot of tall grasses but hardly any other flowering plants have can have much less insects that meadows with a coverage of only like 20% grasses where the rest is taken by a diversity of flowering plants.