Dug up plenty of worms when I was a kid....and turned over many pieces of tin to catch crickets for fishing. No one around here at that time would have ever dreamed of buying worms and crickets at a store....now it's common and raising them is a profitable business.
This reminds me of the one time I tried to mess with the environment, and failed; I was about 11-12 years old at the time.
Up until I was 10, we'd lived in the black-dirt farming area of the Platte River of Nebraska, which always had plenty of worms in the ground. Then we moved up into the heart of the Sandhills of Nebraska, which with its sandy soil had no worms at all.
Upon learning that worms made the ground more fertile, one time when we were visiting where we used to live, I took a shoe-box and filled it with black dirt and worms, bringing it back to the Sandhills, where I dug a hole in the garden and put the black soil and worms in it.
It didn't work; the worms never got fruitful and multiplied. In fact, they just died.