If you go bankrupt or have a foreclosure on the record, it can be hard to move to locations with better opportunities. Many jobs require credit checks, so leaving the job you don't want can be a hassle.
The US household debt to income ratio is far lower than in nations such as Denmark, Sweden, Norway, Netherlands, Switzerland, Ireland, Australia, South Korea, Britain and Canada (see: [1] [2]).
US household debt service payments as a share of disposable income, are near a 40 year low. [3]
[1] https://www.reuters.com/article/us-canada-economy-debt/canad...
[1a] https://i.imgur.com/XRJIDbi.jpg
You can have bankruptcy and have little to no debt for years. A foreclosure, repo, or eviction can happen for various reasons. Maybe you simply got sick and were missing work. You can owe money on your house - a reasonable amount - and be stuck because you can't sell your house nor afford to both pay the current house mortgage and live somewhere else.
Some of the "debt" things are special to being poor. Lose your job and can't pay the final cable bill? Collections. Can't pay the $600 hospital bill? Collections and eventual judgement. It doesn't take a large amount of debt to have it affect your life negatively when a flat tire puts your electricity at risk of being turned off.
https://www.federalreserve.gov/publications/files/2017-repor... (see Dealing with Unexpected Expenses pg. 21)
I'm not familiar with the work structure in those other countries, but guessing there's a far better support structure for retirees compared to the US.