My own sense is that it’s not helpful to characterize a dichotomy between religious belief and “secularism” because, as you rightly note, many who don’t subscribe to the various established mythologies simply substitute a different one. Religion is at core an artifact of the human mind for the purpose of providing a solipsistic self-referential narrative that soothes the believer in the face of a vast impersonal reality utterly beyond their comprehension. While traditional religions have accreted a variety of surface detail over the centuries, they are no different from more modern myths such as the “historical imperative” of Marxism, the “blood purity” of fascism, and the simple-minded chants of populists around the world today. Each provides a narrative suitable for cognitively challenged minds that reassures them of their individual importance and simultaneously provides a group to which they can belong.

Thus the real dichotomy is between the vast majority of people who find solace in simple myths (whether derived from the tribal cults of yesteryear or the pop nonsense of today) versus people who seek to engage with factual reality and accept the fact that our species is here by chance, there’s no Grand Plan, there are no Mummy and Daddy gods or space aliens who are watching over us, and that the only meaning in our lives is whatever we happen to construct for ourselves in an ad hoc manner.

This latter group will always be a tiny fraction of the general population regardless of whatever real-world information becomes available and is subsequently propagated through whatever media happen to exist.