Normally, if someone goes bankrupt, you wipe out the debt and get a fresh start. But that's not permitted with student loans. So the effect is to impoverish many graduates with very high debts.
Throughout history, the only way of restoring stability is to write down the debts. That is treated now as if it's something that can't be done. But it's the only thing that's going to revive the economy.
Basically, unless you're willing to write down debts and save the economy, you're going to have deflation and a steady drain in purchasing power - that is, shrinking markets.
The price decline is a result of having to pay debts. That drains income from the circular flow between production and consumption - that is, between what people are paid when they go to work, and the things that they buy.
As you have to pay more interest and amortization on what you owe, you're left with less and less money to buy goods and services - unless you borrow even more and go further into debt.
Stocks always go down much faster than they go up. That's why it's called a crash. People who put their money into the stocks will find, all of a sudden, that stock prices are no longer being supported by the debt leveraging that's been holding them up.
More and more money is being extracted from of the production and consumption economy to pay the FIRE sector. That's what causes debt deflation and shrinks markets. If you pay the banks, you have less to spend on goods and services.
Mathematically, debts grow exponentially at compound interest. Banks recycle the interest into new loans, so debts grow exponentially, faster than the economy can afford to pay.
Paying debt service to banks leaves less income to buy goods and services.