My mom always washed the tops of cans before opening them.
She said she was in the store once and saw some guy sneezing all over everything, simply not having the courtesy to cover his mouth.
Not to mention the dirt from manufature, insects and vermin that might crawl across the tops of the cans, people, and kids, who touch everything and then put it back, and who knows if they washed their hands after using the john.
I wash my veggies with a couple drops of Dawn. I figure it’s OK to use on the dishes we eat off of, so if I rinse the food well, it will be fine for washing the produce.