Indeed, we can have dual loyalties or we can be hypocrites. Lots of theists who behave more as consumers than as “spiritual” altruists are just hypocrites. They pretend to be Christian or Muslim, but their truth faith is in some secular idol. So I don’t see a problem there.
And I agree that not every pastime has the importance of a religion. Moreover, some idols, crutches, and religions are worse than others.
I don’t say that all theists are secularists who secretly have irrational faith in something. But I suspect that most do, and that enlightenment is rare.
I agree that existential struggle can seem like whining in the First World context, but secular anxiety, depression, and cynicism are real and can be deadly too. These struggles may not be as dramatic and horrific as suffering under the Nazis, but fear of mortality and disgust with the inhuman wilderness, for example, are primordial and foundational. Religions and other frauds and crutches are inauthentic remedies for our existential condition.
Atheists reject theistic religion, but most cling to some faith-based substitute. How could we do otherwise, when Hume, Nietzsche, Darwin, and Freud showed how irrational we are beneath the veneer of our intellectual sophistication?
Do you not see neoliberal consumerism as a striking example of a faith-based, myth-laden collective secular endeavour—along with Soviet communism, Nazism, and Trumpism?