Yea, it can. But if it was as bad as you make it out to be, then we wouldn’t be here. Because our immune system would have killed us off, long ago every time it came across something new.
I’m not suggesting anyone jump into a closed room with a 100 very sick people, but day to day exposure to everything floating around in the air is what teaches the system.
If you want to live in a sterile bubble; a sterile life; knock yourself out. I don’t personally believe your going to do yourself any favors by doing so.
Your call. As is my call - mine.
Not always fatal, but some people do have an overreaction with their immune system when hit by a germ that they don’t have exposure to. Not everyone. TBH, I have weighed out the risks and decided not to perform some kind of total isolation myself. Bubble Boy was a failure.