All currency has always been debt of some sort, be it “do this and you’ll be in my favour” or whatever. The best primer on it comes not from economists, but from an anthropologist… Graeber’s Debt: The last 5000 years basically tells the story. Settlement however, is a different issue.
Private banks without bailouts (key) are a stable system. Look for example at Scottish Free-Banking. One of the actual services banking provides is temporal smoothing: they give us the best signals about future demand by adding now and subtracting in the future, go bust if they’re wrong (key) and that enhances efficiency in the economy.
The real scam and abomination is the central bank. They abrogate the distributed right to prognostication and can print base money, not paired self-neutralizing obligations. Private banking and credit creation functions decently well, even during hard base money regimes, it’s about control. Look up e.g. the Vienna money experiment. Even during a deflation, a local government was able to create a scrip currency that rebooted the economy without having hard money in reserve… the economy is about credit, and in a balanced flow where currency is spent on needs and recycled, that can happen without much net settlement.
Where things have gone wrong is 1) when settlement does not occur primarily in assets, but in printable obligations. (Target2, and the US/China trade imbalance are the two biggest factors here). 2) When base money is created to bail out the private banking system (or to paper over the trade imbalance, where we are today as net foreign accumulation of e.g. treasuries stopped a few years ago).
Re debt: the best framework I have found is from Marvin Minsky. Debt and credit creation is not a problem as long as it funds productive enterprise. If I am loaned $100 and can produce a profit on $10 of new goods every year, the $10 can be used 10 times to pay back the loan, leaving the economy neutral, but with an extra $10/y productive capacity. The issue becomes when debt is used for speculation or, worse, to pay interest that the system runs away.
What is happening now is that people with access to financial capital are swapping it for real assets. Why? Because the carrying cost is 0. Blackrock and the others that are buying out the housing stock (20% of US home sales in May are to people without the intention to move in) are doing it because it’s essentially a free gamble and costs nothing to maintain as long as the Fed doesn’t let rates rise. And if it goes far enough, they will become neo-feudalist barons.
TLDR: It isn’t private credit creation, rather central bank underwriting, that is fueling the current conditions. But they are trapped, as even the most minor cessation of fuel provision will lead to carrying costs and inventory dumping (read: crash)