The Nikkei high was wildly artificial; its price-to-earnings ratio indicated that there was an enormous bubble. The US stock market is (probably) currently inflated, but by a factor closer to 2 (or less) than 10.
(I've looked less into the price of gold, which has a weird place in people's minds and would require a lot more research than I've put into it.)
It's entirely possible, of course, that the US is entering a long-term economic disaster of a kind it has been courting for decades: government borrowing, student loans, Baby Boomer retirement, etc. But US companies have been earning money, and in general that does justify the belief that they merit a stock price that's roughly where it is now; somewhat lower, but not radically different.
Could it be that the E part of the P/E Ratio is currently also significantly inflated? For the tech sector I could definitely see that happening due to the influx of VC money, causing unsustainable b2b spend on cloud&ads, which currently show up as earnings for FAANG but may quickly subside when VCs pull out?
It's entirely possible. Earnings are historically high, and the Fed has been pumping money into the economy for over a decade. But it hasn't translated into higher consumer inflation, which has actually been below the Fed target. So the companies are earning money without raising prices, at least on the consumer basket of goods.
FAANG, as you say, are B2B and don't show up as inflation. It's entirely believable that that's all fake money that will disappear from the market when the going gets tough. Whether it will come back... well, you probably don't want my complete unfocused brain dump which all comes down to "I dunno".
(I've looked less into the price of gold, which has a weird place in people's minds and would require a lot more research than I've put into it.)
It's entirely possible, of course, that the US is entering a long-term economic disaster of a kind it has been courting for decades: government borrowing, student loans, Baby Boomer retirement, etc. But US companies have been earning money, and in general that does justify the belief that they merit a stock price that's roughly where it is now; somewhat lower, but not radically different.