Maybe this helps answer the question of 'where did the bugs go', because windshields aren't as full of them today compared to 20-30 years ago.
wow this would be a neat twist if true - we all defaulted to the negative explanation of having killed them all where a much more positive explanation might be that we're no longer luring them to their deaths at the leading edge of automobiles?
I guess it is most likely some combination of the above, but if there's any evidence it would be a neat reframing
I think they just all collectively got tired of hearing my dad's punny about "it doesn't have the guts to do that again" any time a bug squashed on the windscreen.
My hypothesis is better wind tunnel testing for modern cars so that the bugs go over instead of splatting.
The answer to that is pesticides. There's still plenty of insects ready to smash into your windshield in many parts of the world.