Bad commercial real estate loans (and in some locales, the popping of the residential real estate bubbles) will drag down some banks. Those were what caused the 2008 crisis. Writing down the loans to the value of the collateral is what hits the reserves.
“Bad commercial real estate loans”
Be aware that there are lots of rich Chinese that are looking to buy US real estate as a place to stash their money.
US commercial real estate has the advantage of a high upside.
I suspect most long-term loans are performing quite well. Someone who is carrying a 30-year mortgage at a rate of 3% has every incentive to pay it off meticulously.