No, physically backed currencies will not return because physical goods do not correlate with the size of an economy, especially the amount of gold
You cant do that with bitcoin
This is how you get things like the elderly generation thinking people are just lazy - when they were young, you could fully fund university and have enough for a down-payment on your first home through a part time job. The dollar just went much further. They don't really understand that's not the way things are anymore, especially as most are largely detached from the broader economy.
Also the 'crisis point' you mention is similarly an issue with fiat currencies. Look we're going to print a billion dollars just this once... then 10 billion... then 100 billion.. then they're printing money by the trillions and insisting that the inflation will just be 'transitory', because it always has been, until the one time it isn't. It's akin to somebody arguing that you can always put a bit more air in the balloon - after all it hasn't popped before, so why would it now?
Economies do not grow if their currency is deflationary. If currency gains value over time, actors in the economy are disincentivized from transferring their money to other actors. Less spending means less economic activity; fewer businesses; less investment in high-risk technology research; loans get more expensive; we get stagnation and wealth inequality as individuals with money continue to accumulate it without any incentive to spend it with those who do not have as much.
"But we're in an inflationary environment right now, and there's still extreme wealth inequality" -> That's because our glorious leaders (sarcasm) found a non-currency thing they could subject to deflationary forces: Assets, like stocks and real estate. This was the effect of post-2008 monetary policy; all that extra money had to go somewhere in such a way where it would not cause significant inflation of the monetary supply, so it flooded into assets, which caused a deflationary effect there. Sure, Jeff Bezos has a few tens/hundreds of millions of actual-dollars; but his true wealth is his tens of billions in Amazon stock, which has jumped from ~$4 to ~$250 in the past 20 years.
I don't need to be convinced that printing too much currency is a bad thing and can cause too much inflation; its a matter of degree, not direction. Some might say that we printed way too much money during COVID; but others might argue that the situation would be much, much worse if we hadn't (remember: unemployment hit almost 15% during COVID; the highest number in recorded US history). Currency inflation and asset deflation are good things; but we're experiencing too much of both right now.
Now, just 50 years beyond that point, think about how fragile everything already seems. It's only being held together by massive fed involvement, quantitative easing, and ever more archaic economic concepts like zero or even negative interest rates. And this all during (1) extremely stable years (relative to the World Wars and much more that we previously overcame) and (2) unprecedented growth enabled by the computing revolution. Without these factors, do you really think this experiment would've seen 50?
From 1800 to 1950 there was inflation of less than 50%. [1] From 1971 to 2007 (to go just before your cutoff date) there was inflation of 528%. That in-between era of 1950 to 1971 is when the money printer started. We were still bound by Bretton Woods and so when France made a 'gold call', on all the worthless dollars they had accumulated, we simply defaulted and withdrew. A fun quote from Nixon's treasury secretary at the time, "The dollar is our currency, but it's your problem."
[1] - https://www.minneapolisfed.org/about-us/monetary-policy/infl...
In inflationary systems money becomes worth less, but 'things' tend to hold their value. This is precisely why the very wealthy are accumulating massive amounts of 'things' - it creates profit out of nothing thanks to inflation. So you're most incentivized to buy up as much as you possibly can, and then rent access to it. This is precisely how you get the WEF saying things like, 'You will own nothing, and be happy.'
By contrast in a deflationary system the value of things tends to decrease over time, all other things being equal. That is to say that obviously things like land can still increase in value over time if demand, in an area, significantly outpaces supply, but relative to inflationary systems - the 'natural' direction for prices is down. And so in this system there's much less motivation to hoard things. Of course in exchange there's a far greater motivation to hoard money, but at least that's fairly equitable. Right now lower classes simply can't avoid paying the inflation tax, whereas the wealthy not only avoid paying it, but directly profit off of it.
That's probably not untrue, but that critique doesn't simply make the alternative better. Money becoming worth less, inflation, creates an arguably worse scenario where now wealthy individuals are motivated to hoard things instead of currency. For instance Bill Gates is currently the largest private landowner of farmland in the US. This issue is where you get the WEF also publishing their 'You will own nothing, and be happy.' goal. I find this more unpleasant, and even dystopic, than Scrooge nosediving into his stash of ever more valuable dollars.
Another major issue here is that lower classes are the most unable to deal with inflation. They can squirrel away some money, but in an inflationary system that's the last thing you want to do. For instance stuff like bank CDs are basically just exploiting economically illiterate individuals. Nobody wants money in an inflationary system, but lower classes need immediate access to their money for the next time e.g. their car breaks down, and they are extremely risk averse. The net result of this is a system that not only perpetuates but directly drives ever greater extremes of wealth inequality.
So our current inflationary system only really kicked off in 1971 and is already looking somewhat clearly unsustainable. But what makes this particularly relevant is that 1971 was also right when major breakthroughs in computing were about to unlock a huge economic leap. That helped briefly enable the infinite exponential growth that this inflationary system requires. Without that, I doubt this system would have seen its 50th birthday.
On the topic of stability, the Fed worked to calculate inflation levels from 1800 onward here. [1] You'll notice that from 1800 to 1950 prices never shifted by more than 50% relative to the initial baseline of 51. That's pretty wild if you think about it because it includes the Civil War, both world wars, Great Depression, Spanish Flu, and all of these sort of things. Then in just the relatively calm ~50 years from 1971 to to today, prices increased around 800%.
[1] - https://www.minneapolisfed.org/about-us/monetary-policy/infl...
The amount of currency need not, and arguably should not, scale with the size of the economy. Everything is relative in an economy. When the amount of 'stuff' in an economy grows faster than the amount of currency, then prices decrease - your money becomes worth more - deflation. Vice versa, if the amount of currency in an economy grows faster than the amount of stuff in that economy, then prices increase - inflation.
Inflation is undesirable, but it's in a constant tug-of-war with governments and fiat currency. When governments give themselves the power to print infinite money, they end up doing exactly that, often to the point of destroying their own economy. This is precisely why the Founding Fathers chose the US currency to be coins made of precious metals. It limits the government's ability to damage the country through reckless monetary policy.
Think about how fragile everything is already seeming being glued together by massive fed involvement, quantitative easing, and ever more archaic economic ideas like zero or even negative interest rates. And we're only 50 years into this experiment which, on the scale of something like a broad monetary concept, is barely a blink, and it's starting to come apart at the seams. And this is all during extremely stable years compared to the World Wars and other such events that we overcame in the past.