America is already incredibly religious and the rich/wealthy are no exception. What exactly makes you think that these miserable people are not religious? Because it seems like you're extrapolating miserable = lack of religion, which seems like a nonsensical connection.
Religion has nothing to do with this unless you decide to No True Scotsman and claim that they aren't actually religious. The issue is that they're chasing a lifestyle of endless consumption where at a certain point consumption doesn't actually add anything to your life. Better houses, more cars, wealthier friends, eventually you hit a point where your capital only marginally affects your life until you hop into the hyper-wealthy category. At that point you can start using capital to influence policy but that still relies on personal conviction.
I think OP means religion in the framing context of spiritual belief in a moral philosophy, less in which flavor of the god of Moses you want to throw your sword behind.
Consumerism is, in large part, a religion. Its just, as you describe, a really shitty one. Capitalism for the capitalists is a religion. Totalitarianism for the dictator is a religion. I'd bet a lot of the animators and artists working at Disney and Pixar treat their business model and the company proper as a religion - the experience, the intent, the purpose behind what they do. For the shareholders its just to make gross amounts of money by owning all culture, but for those in the trenches giving their blood they probably feel like they are creating joy and that is a valuable pursuit.
Same for those working at Space X or Tesla or probably even Google and Apple. Most of the employees at those companies drink the kool-aid and have faith.
In those regards, anyone who is just existing, or anyone without faith - and it need not be more complicated than just faith in humanity or the potential for good in people or the promise of the future - is living a hollow, pointless life. And I'd buy that argument.
Religion has nothing to do with this unless you decide to No True Scotsman and claim that they aren't actually religious. The issue is that they're chasing a lifestyle of endless consumption where at a certain point consumption doesn't actually add anything to your life. Better houses, more cars, wealthier friends, eventually you hit a point where your capital only marginally affects your life until you hop into the hyper-wealthy category. At that point you can start using capital to influence policy but that still relies on personal conviction.