I spoke the the rep of Purell when t hey first had their hand sanitizer widely available and they said their product can kill 100% of germs if they wanted it to. But #1 liability, 100% is a very strong statement to make, so 99.99% leaves room for mistakes. #2, your hand needs some bacteria on it, or you will begin to get black spots. Which is what they don't want.
My friends pediatrician said to not clorox everything, let the kid play and play in the dirt. It helps build the immune system. She's a germaphobe prior to covid. Then covid rules cured her. She bucked the system and didn't colorox everything and even started to shake peoples hands. She was like Howey Mandell, but worst, she wouldn't even fist bump.