Basically I agree: most advice for most people is going to be very similar. However I can see added value in enhancing engagement with that advice by, for example, linking it to that person's specific behaviour.

Abstract example: If I told you to exercise optimally, you'd snore. If I said that having analysed your behaviour over rather last month, you'd benefit from two additional HIT sessions each week... I guess you'd care more. Even more so, if it told you it'd help you fit into your bridesmaid dress for the upcoming wedding... you see where I'm going with this.

Most advice is generic, but compliance is poor, and that gap is where more of the untapped benefit is to be found.

I'm not sure how you got that from reading the article. "As an example, exercise and daily caffeine intake emerged as strong predictors of mood for one participant, but for another, it was sleep and stress that were more predictive, while in a third subject, the top predictors were brain function and cognitive responses to rewards."