loans are a bet on the future
I think loans are definitely a bet on the future – not necessarily on growth, but on the future being a whole lot like the present. Namely, that you will continue to have (at least) the same nominal flow in 10 years that you do right now.
Flow likely depends on your value-add, which in many cases may be a derivative of net energy in some way. So long term debt – definitely, its a bet that the flow will be at least steady for the duration of the loan.
If economies contract, all hell breaks loose. Not because the interest wasn't created, but because when credit growth goes into reverse, the flow doesn't just slow down in proportion to the drop in credit growth, it slows down at some multiple of that because of a change in confidence. Confidence affects many things.
When confidence shifts, people suddenly decide, "I need to triple my savings", and so flow promptly drops by some decent amount even though at least temporarily, surplus remains the same. And on top of that, no new money is created because confidence also drives "what's my acceptable debt-to-income ratio?" And then, tax payments drop. And then, people lose jobs, decreasing tax payments and flow.
After a while, borrowers already on the edge (with ponzi, and speculative debt) default, this transmits an increased lack of confidence to peope, and then even fewer loans are created, more money is saved, etc, etc.
Tweak that one variable, confidence, and that's what causes the cascade down. The bigger the ponzi finance element in place, the more dramatic the unwind.