This may sound pedantic but the cause is so simple it should be obvious: paper doesn't weigh as much. Therefore it's easier to push and so you get more "paper pushers" or "bullshit" jobs.
I guess the crazy part is, fundamentally, I'm being serious. If you need to dig into the ground to get your money, and can't just print more by pressing a button, human nature will make you less profligate.
1. Paper money vs fiat money : most economies were fully paper money decades before switching to fiat. Fiat did not meaningfuy change the daily manipulation of money (and today we are largely digital).
2. Paper pushing vs money handling - I think paper pushing even in literal sense existed hundreds of years ago e.g. Various administrative tasks in the Ottoman empire, if not thousands years ago in Roman empire, let alone catholic church etc.
3. Value generation - you can still dig for gold today to obtain money; but long before fiat it was not primary method of value generation for superlative majority of population. In other words we handled paper money, pushed paper administratively (literally and figuratively), and mostly stopped digging for gold long before fiat.
I'm not sure why you think item #1 is relevant. Especially since you seem to be referring to modern economies. That said, there is certainly historic evidence that currency debasement has caused economies to fail, right?
As far as #2 is concerned, I don't contend that "paper pushing" or "busy/BS work" didn't exist in hard currency environments. What I'm suggesting is that the proportion of it increases with a fiat currency. Specifically because profligacy is normalized.
Perhaps if we compare the public sector size of individual countries with their debt/gdp we'll see a correlation?
And, to address #3, although a person can still dig for gold to get money... there's no obligation (law) that makes anyone accept it as payment. And, more importantly, you can't pay your taxes with it. Which means gold (or any other unofficial/alternative currency) has an inefficiency imposed on it by the state. So your final point seems incomplete and therefore inadequate in disputing the hypothesis.
Bear in mind, I'm not completely sure myself... it's mostly my intuition. Another reply contends that the root cause is over-financialization which, to me, is also fair. That'd imply fiat currency was merely an artifact. Determining attribution can certainly be challenging - as they say - correlation does not imply causality (-:
So, I'm just trying to think it through in a simple, constructive manner to explain the perceived anomalies like massive wealth disparity. Which, I'd guess has grown significantly since the start of civilization.
I assume you think there's always been a relatively constant amount of "paper pushing" or so called "bs/busy" work? What makes you say that? Or are you just assuming that's a base case? Is it plausible that in ancient times people could sit around and do nothing without suffering a quick death from the elements?
How can we explain the ever increasing pay/wealth gap if some people aren't accumulating wealth for doing less "work"? Did the variation in human ability increase over time? I guess that's a possibility. And I find that there's never a single cause when trying to explain complex phenomenon. Nonetheless, it's an interesting exercise.
I guess the crazy part is, fundamentally, I'm being serious. If you need to dig into the ground to get your money, and can't just print more by pressing a button, human nature will make you less profligate.
Do you find that to be crazy? Unreasonable?