Sure, but it's not like humans in all parts of the world haven't been proposing models for understanding happiness in some form or another since before the writ

Sure, but it's not like humans in all parts of the world haven't been proposing models for understanding happiness in some form or another since before the written word. If it were possible to compare every model for happiness ever conceived, they'll likely have a few things in common. Mostly, they will propose factors that are familiar within a group's common frame of reference, those factors will address that group's common experiences and habits, and the formula will project a roadmap for making changes in those habits to realign the experiences with "happiness." In other words, "we all tend to do one thing, but doing another is probably better, and it's easy to forget, so here's way to remember." If it's useful to anyone at all, it's of value. If it's useful to larger group, then a utilitarian might say it has greater value. But even the assessment of value is culturally-dependent, so it's kind of pointless to argue about the virtues of different models on the basis of their cultures of origin. So of course different cultures present things differently. It doesn't have to mean anyone is losing the roots of their own culture. Foucault would argue that being anything other than a part of your own culture is impossible. Even if you reject your own culture, you're rejecting the culture you're a part of, and that becomes a part of that culture. You just can't _not_ be who you are, where you are, and a product of your experiences. If the differences in habits among various cultures become more apparent in a direct comparison, that's mostly down to the different frames of reference that determine the signs and signifiers used to express and internalize the models. But within each culture, the mechanisms themselves are often fundamentally the same. We manage resources as a group, we figure out who's us and who's them, we defend the group against threats, and we generally aim to reproduce. Whatever else goes on, our culture is how we communicate among ourselves what to expect from each other as we all go about those activities. It gives us the language we use, which Pinkerton et al might go so far as to say shapes the very ideas we have about ourselves and each other, including our "secrets to happiness." The point is, there are many models for understanding happiness. Some we know more about because they've established a large socio-economic footprint, like the major religions, and some are more academic thought experiments, like what the ancient greeks tended to get up to. Others are more directly products of and by their host culture. Ikigai is this. If people find it accessible and useful, that's nothing but great. Is it a very Japanese way of looking at it? Sure. Is it some innate universal truth and wisdom? I dunno, but I bet someone pushing that narrative has a book or a seminar to sell. In any case, for most purposes, the meme is probably enough. Do what you can to do what you love, that you're good at, that helps you survive, that helps your group survive. In "westerner" kindergarten, they simplify it even further: do only what is necessary, helpful, and/or kind. Don't even need a graduate philosophy degree for that.