I think you are correct that science alone cannot tell us a meaning of life. But I think you’re wrong that traditional sources of meaning don’t make any scientific claims. They make tons of them: about the creation of the Earth and its place in the cosmos, about the creation of humans and our relationship with other species, about the nature of the human mind, about human history, about geological history, about health and nutrition, and so on. And that’s just religion. Tribalist ideologies like ethnic nationalism make tons of claims about the group’s history and origins, and often make claims about the group’s innate superiority. These claims are all subject to scrutiny by science, and they have done very poorly under that scrutiny.

Of course it is always an option for religion to try to explain the old claims away as allegorical or misunderstood, but that leaves one with a very different kind of faith than someone who believed all of the claims fully and literally, with no reasonable doubt in their mind. Everything from the spread of disease to the fortunes of war to the success and failure of crops was once earnestly believed to be caused by the will of god or gods. Even the most ardent fundamentalist today cannot really get away without accepting—at least implicitly—materialist explanations for why many things happen. Even fanatics check the weather forecast.

Modernity has also worn down the appeal of the old sources of meaning in other ways than through science.

Affluence, health, and security have taken a lot of the appeal out of religion. Getting on the good side of an all-powerful god was a lot more appealing when famine, disease, and violence could strike at any time. We all still feel like we’re at the mercy of the world sometimes, but many of us are fortunate enough to avoid the kind of physical insecurity that our ancestors faced, and religion has declined over a few generations in every place where these fears have receded.

Tribalism too has been sapped of its potency by the decline of endemic violence. Fear of the out-group is a lot more powerful when a violent death at their hands is a common fate of the people you know. In addition, the rise of fast, cheap travel has made it harder to believe that your home and your people are “the greatest on Earth” while all others are inferior. Among the classes with the disposable income to travel internationally, nationalism has grown very weak indeed.

Ideally we would find something better than consumerism and celebrity-worship with which to replace these crumbled idols. We certainly cannot go back: the damage is real and it is done. Each new wave of religious or tribalist revival crests lower than the last. Not to mention, the traditional sources of meaning had awful drawbacks and excesses, as you alluded to. I hope we can do better than a choice between nihilism and the miserable past.