In the beginning, states did have laws. I know Rhode Island did. I believe that a federation of 50 states could offer a lot of religious freedom. You need an abortion? Go to MA: it's officially atheist. You don't want to run into Muslims? Go to Texas: Muslims are not allowed.
It's a matter of granularity. The Founders set up a system that could allow many choices and a great deal of freedom. Over time, the tyrants decided that one-size-fits-all was a better idea, and the one-size became: freedom from religion.
And look where we are.
But would you really want a system like that? Christianity isn’t the only religion in the US. What would happen to religious people in MA? Could your Jewish city council ban the consumption of pork or shellfish in city limits? If you want pork, give up your home and job and move. 3 towns over.
Think about how you would balk at laws written to satisfy someone else’s religion. No pork, no shellfish, no blood transfusions, not being to celebrate Christmas, or dress up your kids for Halloween, ect. That’s how the rest of us would feel about laws that you’d want passed because of your religion.Any act you do in your normal life is against someone’s religion. You are free to do it because, as a non-adherent to that religion, you aren’t bound to its laws. I prefer this system where you are free to live your life the way you want, and I am free to do the same. Nothing I do in my life hurts you or the practice of your faith. Not everyone shares your faith. We shouldn’t be made to live the way you want.