I’m no whatever studies that but wouldn’t there be a difference between using a stone to smash open a coconut and sharpening a stone, attaching it to a stick, and chopping down a tree with it?
Yes, there is.
But plenty of animals don’t just pick up things they can use, but actually make tools for specific tasks.
Crows for example have shown they can bend wire into a hook to fetch food out of a container.
Apes can and do sharpen stones they want to use as tools.
The historical context here is that’s how you cracked eggs in the middle ages, before they had our modern egg-cracking technology. You balanced the egg on the head of a priest or monk and then hit it with a rock. So the excitement comes from the imminent enjoyment of a freshly cracked egg.