The decline of insects is the scariest thing I've seen in life, and I mean that. We kicked the bottom out of the food chain. It's hard to state what I experienced as a child 40-50 years ago vs. now.
In just 3 years I've seen the insect population tank at my camp. My camp in the swamp. Banana spiders were legion, there's still a few. The ground spiders are half what they were. Used to get a hummingbird now and again. Nothing has touched my feeders in 2 years. Further up the food chain, I see very little "higher" organisms. Nothing but squirrels, no other mammals. And that's only 3 years.
Hell, my front porch is turning into a wasteland, and that's on the bleeding edge of town, surrounded by country. Used to get as many a 5 tree frogs at a time, 0 now. 4-5 hummingbirds every year, now I rarely see 1. My porch lights used to be covered in dead bugs, pretty clean now and I haven't touched them since last summer.
Young people have been robbed of a world they don't know existed. Robbed in ways that don't make headlines.