I very much agree with that. Unfortunately that idea is antithetical to most religious people because most religions claim that they are the only valid religion

I very much agree with that. Unfortunately that idea is antithetical to most religious people because most religions claim that they are the only valid religion. Teaching a kid about the variety of beliefs across the globe and the option of none is likely to make the kid less attached to the bubble of the religion of their parents. In my country, religion is a 1h/week class from 1'st to 12'th grade and parents have to explicitly opt-out of it if they do not want kids to take part. Opting out is also slightly detrimental to a kids scores. What is thought is pure indoctrination and there is no element of multi-religious sociology and anthropology.