system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why must water be boiled to be considered safe while food only needs to be cooked to 165 degrees to be safe? If I washed my ground beef off in the mountain stream, would I then need to cook it to 212 degrees? Mmm...charcoal burgers!
gpt
It has to do with the type of bacteria that live in different parts of the material you are heating.

Water is a fluid so it has bacteria all mixed in. The entirety of the water needs to be boiled so that the entirety of the bacteria dies. 

For meat, the majority of the bacteria is on the surface of the meat which gets WAY hotter than 212F. More like 300-400F. When you sear a piece of meat you are instantly killing most bacteria on the surface. 

The INTERNAL temperature has to be at least 165 degrees for at least X amount of time to kill off all of the microorganisms that live INSIDE the meat; and even that is just a suggestion. You could eat super rare (but seared) meat 5 days a week for a year and never get sick, then that one piece of meat has something alive inside that didnt get cooked out and you get parasites. 

When beef (for instance) is very safely sourced (like a super fancy restaurant), they can offer it extremely rare, because they sear the surfaces to kill the surface bacteria, and they are certain there are no parasites/other diseases inside.