I needed a clarification, Wikipedia had your back.
The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species.
Note that this is described species. Beetles are really easy to preserve and are often super cool. There are likely more species in other orders, but they haven't had as much work done on them. Hymenoptera, for example, with all of the parasitic wasps probably has more species but they can be so freaking small and difficult to work with.
Sorry, I am like a wanna be entomologist who works with akshual entomologists and this is one of the things that triggers them
I recently heard a tidbit that we think there's less bugs in the air because windshields aren't as dirty. Like, if that's our indicator on such a huge and fundamental part of life on this planet... Less bugs on the windshield. We have no idea
It's not even very good logic (in my humble, non-expert opinion). There are more cars about, so even if the number of bugs was the same there would be less bugs per car, and that ignores that cars are more aerodynamic and so are probably just killing less bugs anyway!
The aerodynamic thing is where money is at. I drive a 91 jeep and I still have to use the windo washer at the gas station, cause the wipers are insufficient.