> How on Earth do people afford a house (I mean, $300,000 is more than 3× my expected salary, and where I am, that barely gets you a townhome)?

Most young people in the world can't afford a house. They rent apartments or stay with parents until their jobs pay more and they accumulate savings in the meantime - or, alternatively, they shacked themselves with decades of debt and get a mortgage (not everyone is mentally built for that though). Also, many people never decide to buy a house, and just get a (cheaper) flat instead.