Learning about other cultures and other people’s way of life is incredibly important in an increasingly divided world. I strongly believe that if the average American spent time living with an Islamic family in the Middle East for a weekDuring the Colonial era, quite a lot of indigenous peoples were wiped out by exposure to new diseases. Last I checked, we still haven't figured out what caused Gulf War Syndrome, much less how to cure it.
I'm convinced that there are a lot more health problems related to traveling and having no understanding of what we are exposing ourselves to than gets recognized, and there are plenty of stories out there of people bringing back horrifying health issues from their honeymoon or whatever. (I'm thinking of some article about some couple that picked up some parasitic worm from walking on the beach. The photos were disturbing.)
And it can be an issue that a local wouldn't have a big problem with. Maybe they have immunity or maybe they know not do X or whatever.
I don't want to shut travel down entirely, but I think ideas like yours contain very, very large blind spots.