I'm not going to approach your strawman about eating dirt.

I'm just going to say this:

There's microbes constantly in the air around you at all times that you're constantly inhaling, on every surface you touch, everywhere you go, every person you interact with. Billions or Trillions of different strains you encounter daily. Your skin is covered in microbes at all times. Your body has more microbes inside of it than it's own cells(google it).

At any point you could have a reaction to one of these but you don't because of your immune system.

Some people who have weak immune systems or are susceptible can have problems. BUT this is hugely statistically unlikely.

So for the media to be drumming up fears of microbes in the air is disengenuous and for people to be falling for it is truly something and says alot about the state of modern scientific education.