> However, it isn't yet obvious that it can be done without - a religion's adherents are often people who want some sort of power structure telling them what they should do to be a good person.
There are countries where the majority is not religious and they function just fine.
Are they? Much of Europe and Japan have fallen into economic doldrums with declining birth rates, and fallen prey to advancing right-wing populist movements. But then Poland is quite religious and far rightists are taking root there as well, so maybe religion isn’t the sticking factor.
It's also notable that those countries don't have noticeably worse standards of living than countries with a state religion or less religious freedom, and Europe attracts many migrants from such countries.
There are countries where the majority is not religious and they function just fine.