I looked at materials hidden in my desk for one question during a quiz in fifth grade and it still gnaws at me. Cheaters suck.
The postgrad continuum mechanics class (I think taught by the geophysics department?) was the biggest exception so I’m betting there’s quite a bit of variance among fields.
I don’t doubt there’s academic fraud (living in the dorm my first year wiped away any illusion) but within my major it didn’t end well.
People did plenty of collaboration on homework sets. Some of the harder ones were almost impossible unless you did, like those 20 page Phys98 homework sets...
Did people report them?