Our debt is in part due to heavily subsidised tuition fees. Students cost about $15k a year, of which only 3k is paid as tuition and the remainder by the government. In the US many students average 10k tuition fees, or a multiplier for private universities.

0% interest also helps prevent debt from blowing up here.

And most students having multiple world top 5% universities within 1 hour by free public transport, also helps as students can spend part of their student life living at home, it's a lifestyle choice, not a necessity for many to move out.