By letting people do what they want how are people ever supposed to know who is right or wrong? What's the right moral choice and what isn't? You could create an authoritarian system based on pure logic to give meaning to people's lives and hold them accountable, but people aren't logical all the time and in essence you are low key admitting that the nature of reality is still nihilistic if you don't embrace religious truth.
I've started to believe that religion is the best way to protect people from the worst aspects of their nature and bring order into society for this. People need to let go of their hatred towards ethical truth and authorities.