This isn't just a U.S. issue.
Considering every developed country in the world has essentially the same requirements concerning vaccines, how many "experts" are you willing to ignore?
The vaccination schedules are becoming more and more important due to the increase in immigrants from third world countries.
A lot of other countries have many less vaccines on their schedules and also have a lower infant mortality rate. maybe those two things are related and maybe not. The US used to have many less vaccines on their schedule and had a lower infant mortality rate. Maybe related and maybe not. I haven’t come across anything that explains why that is to my satisfaction.