I am not one of those anti-vaxx loonies who are like “you got an immune system so you’re fine without all this crap”, however isn’t it an accepted view that the immune system needs training to operate well? Hygiene hypothesis comes to mind and especially during those years as a child many parts of the immune system are forming and developing.
Going too clean everywhere will counter that and lead to worse outcomes later in life if you get sick with something. So while I sympathise as a parent with a preschooler who is terrible when sick, it is useful to not be too super clean in that environment.
Now in areas where more grown-ups are working, office spaces and so on, sure. Not quite against that.
A train once bit my sister…