You can see for yourself how the debt-to-income ratio for the median household went up in the past 20 years:
The Federal Reserve Board of Governors in Washington DC.
www.federalreserve.gov
You'll be surprised at people's mortgage in relationship to their net worth. For most people in the middle class, their house is their primary investment vehicle. They are definitely taking out a loan to get a house. The average person in the US is loaded with debt, as encouraged by the monetary and fiscal policy. So they get houses and cars and iphones that they cannot afford. Let's say you're one of the lucky 2er% and you're a tech bro making $300,000 / year. Sure you're rich compared to the median national income but you're competing for houses with other tech bros and will take out a huge loan to acquire a house that cost over $1 million to live in or near Silicon Valley. How is the average person making median salary (think government worker) able to compete for housing in Silicon Valley?
If interest rates go up, if mortgage rates are not locked, there will be defaults -- lots of defaults. And during rising interest rates regimes, liquidity dries up. When people feel poorer, they spend less and that results in job losses (if they even have jobs). Banks are less hesitant to loan or will loan at higher interest rates during this time if they want to tap into whatever housing equity they have. Of course, housing equity will decrease as houses are worth less with higher interest rates. This is a recipe for foreclose and deflationary pressures which will spiral into it's own feedback loop and if unchecked will get out of control. Think GFC of 2008. The government will be forced to lower interest rates and inject money into the economy.
Interest rates cannot go up for the long-term. Interest rates will remain low which makes bonds unattractive relative to inflation. This drives up prices for equity and real estate and cryptoassets and other scarce assets.
Overall, the current structure of the economy is broken and unsustainable. I do wonder if cryptoassets will outperform equity over the next 10 years.