Okay, but what if their carelessness about privacy directly or indirectly affects you? For instacne, if someone in your contacts doesn’t prioritize privacy and has granted apps access to their contacts, it could potentially expose your information indirectly.

I understand this and every other example you point out, but let's be real: I can't physically check what my friends, family and beloved ones do with my (meta)data without heavily invading their privacy (that's ironic) or schooling them about how evil GAFAM are and so on. Most of my friends aren't also technically inclined, so it would be both a waste of time and a source of useless arguments. I just do my part and I can't do more. Neither can you, frankly.