@rocks you're conclusion is 100% correct. That's where the trust in the system comes from that's where the risk is. That model doesn't need a more secure payment Chanel. It's not a failure in the money that breaks the deal but a misguided business choice.This is confusing bank created credit with supplier credit, these are two completely different things.
Bank created credit is all the things you said, it is false creation of money, artificially lowers borrowing costs, artificially lowers savings return and artificially expands the money supply and inflation. Bank credit is the problem Bitcoin is here to fix.
Supplier credit is none of this though, it is simply a delay in payment (for example pay 90 days after delivery). A supplier is not lending money, it is lending time value of a product. Accounting wise it appears as a loan on the books, but no money was created or exchanged.
My example was a simple one to show how supplier provided credit can make a supply chain more efficient by lowering the working capital costs of downstream participants. This allows downstream participants to operate more lean from a financial perspective and lowers the cost markup they charge.
Suppliers (not banks) will offer this credit (again not a money loan but a delay in payment) because doing so benefits the supplier by lowering the markup charged by other areas of a value chain, which enables the supplier to capture more of the total profit.
If LN was used in these B2B transactions, it not only prevents suppliers from offering credit but reverses the flow of money and forces downstream participants to pre-pay. This in turn would both lower the profit of the supplier while also raising the cost of downstream participants to operate (their working capital would increase and they would have to go to banks to take larger loans). Here both sides would prefer the current supplier credit model to an LN pre-payment model.
My basic point is most industries are very well optimized financially already and there is little room left for improvement by reorganizing finances. To make something like LN work you have to really understand the reasons behind the payment flows, not just say "hey we automated and secured this type of payment" because that usually will not be enough. This is why I don't think LN will ever be a broadly used B2B payment method. I would expect suppliers and purchasers in a Bitcoin world to be scheduling payments the same as they do today...
But there is not as big a difference between bank and supplier credit as you infer. The efficiency in the supply chain working capital are still vulnerable to malinvestment.
In the case where a supplier gives credit to a retailer for stock and the retailer can't sell it, it could be the retailer who made a bad order but it's the supplier who is short payment. It still contributes to the business cycle in some way either as monetary inflation or price deflation.
In this situation the retailer could take bank credit to pay. The fact that overstock.com exists is testimony to this.