You claim to be afraid of a world where everyone dresses and talks the same, yet you want an earth where you spend most of your time living in a small slice of the world, where everyone talks and dresses the same? I don't really see the difference at that point tbh. I live in a very multicultural part of the US where I get to interact with foreigners, tourists, and immigrants on a daily basis, and far from "turning into a giant mush" or "everyone talks and dresses the same", it encourages you to look outward and to learn stuff you wouldn't otherwise have motivated to. If I wasn't a child of a multicultural family and didn't grow up traveling frequently, no way I would've even attempted to learn some German, Japanese, and Hawaiian alongside my native English.