I know several people who made out like bandits buying in Florida and Arizona in 2010 and only held for 3-4 years.
This kind of thing is what puts me off real estate investing. The idea that I would be a beneficiary of an enormous crisis leaves a bad taste in my mouth. I'm not stupid, I know that someone is going to make that profit, but it doesn't have to be me. Similarly, the idea of putting myself in the position of one day needing to deprive someone of their housing if they're unable to pay is something I'd strongly prefer to avoid.
Also, you never have to deprive someone of their housing if they are unable to pay. You can work out payment plans and all sorts of compromises to get through tough times and tenants will generally appreciate that flexibility.
The point remains - real estate is more stable for side income than a bar!
Worth noting that even in "normal" times, the banks and money lenders are benefitting due to the parasitic and immoral practice of lending money with usury (aka interest), which is one of the major cause of financial crises that have and keep on happening. It's baked into the system.
This is the difficult part.