Actually, cross contamination can give you food poisoning. All any food scientist, or just Google it. That said, most incidences of food poisoning occur in the home, not in restaurants.
That's true. And I don't have any studies or stats to cite but I'm pretty sure that the cross-contamination that causes food poisoning or other sicknesses in the home usually involves chickens and cutting boards.
It's just that chickens are often contaminated. Cooking kills the bacteria. But when you cut raw chicken on a surface that surface gets contaminated. Then if the next food on the cutting board is not going to be cooked → Food poisoning.
In restaurants, surfaces are disinfected daily. At home, not so much. And the grooves made by knives in a wooden cutting board are great places for bacteria to lurk and ambush the unsuspecting.
@ThaiVegan is exaggerating when she says "a few tiny molecules". But foodborne illness can be caused by bacteria that are literally microscopic. Keep in mind that the human body is pretty good at fighting off bacteria. So that is why we don't have a big line at the emergency room. but it depends on the size of the dose, the species of bacteria and the size and health of the patient.