Why can’t humans drink water directly from a river like other animals in the forest or eat food directly from the ground like dogs and cats? After all, aren’t we animals like them?
Humans can and do eat stuff like berries, fruits, and vegetables directly picked from the plant.
Humans can also drink water from rivers and brooks. But they only do that when it’s considered safe, far away from other people, like in the mountains and in wilderness when hiking.
Close to populated areas, the water in a river may be polluted, and if you drink it you may get some bug or parasite. But you can do it, and survive.
You may have noted that dogs and cats needs to be dewormed now and then. Wild predators always have intestinal parasites. Fish often have parasite eggs or parasites in their meat. That’s why we make sure to kill off any parasites before eating it, either by cooking or by freezing it, in the case of sushi.