Much of the economy is a "who blinks first" situation, tied in with human emotions and drives.
Consider also that at its core, an economy isn't money at all - it's goods and services and money is just a tool that at its best facilitates balancing production of goods and services with desire for goods and services. At its worst, money creates massive imbalance.
The curious thing about those with capital reserves holding it tight (and so causing a recession) is - what are they afraid of losing? If they could spend $1M today to keep 20 people employed for a year making widgets, are they really better off if they fire them instead and just sit on the $1M? The calculus must be "I think if I spend that $1M this year, I may not actually be able to sell anything at all and so will lose money, but if I hold that $1M, I'll at least have $1M at the end of the year."
But if too many people do this - then there won't be anything left to buy; in the reductio ad absurdum they would have their $1M but there would be zero goods and services.
Ultimately this is an odd artifact of extreme specialization: at least in medieval times, the owner-class had, at the end of a year, food and clothing and basic resources. Today, most owner-classes don't actually produce necessities, so they'd rather just sit on their cash reserves and buy the excess produce from those that do make basic resources.
Is the problem bankruptcy law? Is it over-specialization? Is it the lack of a buyer of last resort, always providing incentive to keep production up of some products when there is little demand - or to ensure there is a reasonable reserve if there is a supply disruption such as with war or pandemic?
That is - we have a strategic petroleum reserve, should we have strategic housing reserve? Strategic automobile reserve? Strategic food reserves? Strategic clothing reserves?
(Sorry, this was kind of a random collection of topics...)