Why 30 is the decade friends disappear
It's because your cities are bad.Wait, let me explain. Around 30 is the age people start having a bit of financial independence and put down a mortgage on a place in the suburbs, move, and start a family. Noble and normal goals, except that in North America (and other anglosphere countries) the suburbs are hugely spread out and isolated from the city and other people not in your immediate street. What are the chances your friend group all decide to live in the same suburb, let alone the same street? You're already spending most of your free time driving to and from work, how much do you time do you have left after meals, kids and shopping to spend more time driving to your friend's suburb to hang out?