Fun fact, e. Coli is a family of bacteria, most of them are harmless to humans. They are even a part of many diet supplements.
Also I don't know where you live and what your food standards are, but here in Europe you can drink raw milk quite safely and there are plenty of raw milk products like cheese. It's literally a non issue.
Have you actually talked to a microbiologist about this? It's not safe at all.
E.coli might have some harmless strains, but you have no guarantee which strain is present. It's also not the only dangerous pathogen found in milk. Did I mention raw milk is often contaminated with bacteria from cow poo?
Just because something is fine for a calf doesn't mean it's fine for you and vice versa.
Edit: oh yeah and I live in England. We have decent food safety standards here and that's why raw milk isn't sold at supermarkets.
Raw milk is not sold at supermarkets because its shelf life is like one day. But you can buy raw milk directly from farmers or even from the Borough Market.
It's already infected with the bad bacteria, and is a great growth medium for them. Also not everything you buy has bad bacteria or only has bad bacteria on the outside. Like you wouldn't expect fresh fruit to have bacteria inside it because it's a living thing with the ability to defend itself. Cooking food kills most bacteria too; that's why pasteurizing things works.
Raw milk is known to be a major health risk, why would you just ignore it? Like you wouldn't eat raw chicken so why milk?