Freedom of religion is mostly obsolete, because most of it is included in freedom of speech and thought.

I am not convinced it is 100% obsolete, because religion includes some practices of worship that people should also have the right to do, within reason (as long as they don't violate others' rights). For instance, the Religious Freedom Restauration Act was adopted so that people wouldn't get fired for their (lawful) religious practices. That's not included in freedom of speech and thought.

However, if the US banned firing people over things irrelevant to their jobs, this aspect of religious freedom would also be superseded.