A Simpler Explanation ?
Could it be a simple loss of incentive ? If person A cannot make a profit anymore, cannot gain something by "working" or "investing" or any activity, economic activity anymore, cannot gain "an upper hand", or "win something against another person", or make a gain, especially a gain against another person or entity, especially a "win" to the detriment of another person, which makes it more "valuable" (since you gain and the other suffers, and it makes you feel better, superior and good and so forth), person A will stop doing, will stop "working", will stop investing, will stop doing anything, just like the NEETS (not in education or working).
And this can be the real situation of the "Economy" worldwide and in general, it is harder and harder to make investments, work and gain: case in point, if you do find a job anywhere, as soon as you want to do something more, you want something else, like get out of living in your mom's basement and maybe rent your own small home to rent (for a kid) the cost of renting takes away such a large chunk of your salary that it is just not worth it, it is just not worth it anymore, why work and not have anything left when it all goes away for rent and other obligatory expenses ? So there is no longer any incentive. And so it is with many endeavors, many situations where profits are minimal, because markets are saturated, or can be easily saturated and so forth. You can work and keep on living in your mom's basement and save some cash and then what ? buy a new car and take some trips and those 20,000 dollars of cash you saved up in 2 or 3 years all goes down the drain anyways, many think it is not even worth working at all anymore, who cares about a few trips and a new car ?
So the economy stops, starts contracting and so on. Bubbles are the only thing that can prop it up, get it going again, albeit for only a temporary period of time, a temporary illusion that so many people can make a killer gain by buying and increasing home prices for example or dot com web sites (like in the period from 1997 to 2002). We need illusions, make believes, bubbles, we need INFLATION more than anything else, inflating prices giving the illusion of making a gain, inflating HEALTH CARE prices to give the incentives to work in HEALTH CARE (and make everyone feel sick and believe they are sick and they will need and make them need ever more health care) or COLLEGE PRICES, bubbles and make believes, a temporary illusion that something normal, something average is all of a sudden worth a lot more, brainwash people and even if it only lasts a few years you will make a killing profit on it and so forth. A temporary falsification of reality, a temporary fairy tale everyone believes in and generates a lot of economic activity that is destined to end, the perfect example is home price inflations and McMansions and everyone buying McMansions on loaned money that will never be paid back again and so forth. Or the "START UP" mythology, everyone starting their own company thinking they will be the new Bill Gates, all these great inventers making it big (how can people believe such BS ? inventing something new and profitable is something that happens once in a blue moon, everything else is a make believe bubble, is an illusion, only one in ten thousand can possibly make it big). Notice people don't want "NORMAL" don't want a simple job, a decent salary and low home prices and rents, they all want to be superstars and by wanting this they all become poor slobs in the end, a poorer and poorer society.
But the game ends, these kinds of games end, you can only invent and force so many bubbles in the end, people may start learning their lesson and not buy into all the HIGH REAL ESTATE values and prices anymore and so on (although there is no limit on how stupid and repetitive people are and how much you can fool them and how many times they can fall into the same traps).
The economy did well from 1950 to 2000 only because of a given combination of mutual gains and decently priced goods and a decent amount of work for a lot of people given the technological level of those decades and so forth: that was a quirk, a momentary quirk of conditions that will never come back again (no outsourcing and chinese workers taking your job away and so forth).
So given this situation of economies destined to naturally contract and run out of gas in the long run as all incentives to do anything decrease, the bubbles fade away, the profits become minimum and so on and it becomes harder and harder to gain an upper hand against anyone else at all, what can be done ?
Huge government projects, huge construction projects building trillions of skyscrapers and new homes and new high speed train lines and rockets to Mars, huge public works hiring millions even to do nothing at all all across the world, as there really is very little new possible work needing to be done anyways, free salaries and cheap rents, we must get out of this idea that a profit based, profit seeking economy will get us anywhere anymore and embrace huge consumerism and government led and enforced economies creating huge projects free salaries and cheap rents.
Half of Philadelphia is made up of old crappy homes, tear it all down and build millions of new skyscrapers, cheaply priced luxury apartments and so on and then ten years later tear it all down again and build huge suburbs all over it again, all over again and so on, force development and projects, colonize Mars and so forth.
Will this be done ? No, all the economic politics worldwide are doing the exact opposite, firing government workers, closing factories (no profit, no work) everything is contacting, there is no future, all in punishment mode. The end result will be greater and greater poverty for all. Now keep on saying that people are lazy slobs and must be fired, go on keep on saying that we don't need to pay taxes (since taxes pay other people) and they are robbing "your hard earned money" and all other kinds of BS, keep on saying they need more "education and training" more "innovation" and research to "create jobs" when no one on earth really even understands any of how all this BS can be connected to new jobs and job creation when more innovation and reserarch and education's principle and major goal is to eliminate jobs and automate work, is to kill jobs so that greater profits can be made for the fewer and fewer enterprise owners and so forth.