When I grew up we had grasshoppers in every lawn, always and everywhere. These days I hardly see or hear any.
My parents would talk all the time about catching lightning bugs as kids. Growing up in the 80s and 90s, I didn't see a single one. Now, the back yard is absolutely full of them (again, apparently.)
I'm also extremely grateful that they're smaller than us. A dog sized mantis would be the stuff of nightmares and horse sized mantises would pretty much have guaranteed our extinction long before now.