That's a multitrillion dollar question. One difference is that the US is printing the global currency, while Japan was creating local convertible currency. We are also seeing the stock market decoupling from the underlying economic reality. The dynamics could be different. I am personally becoming worried about the USD cash (large) part of my portfolio.
I agree with your assessment, the yen is a small fraction of the global reserve currency pool compared to the USD, dollar denominated debts destroy the competitiveness of other economies which can be seen when you graph the DXY against emerging market etfs. There is no alternative to the dollar right now but there is also no real alternative to the manufacturing and materials base in China. Domestically alone China can source a significant amount of material and in many sectors they supply the majority of mining output for the world, next after them is usually Russia. The US's purchasing power and GDP only exists because the world trades using dollars. It amazes me that more people that post on hacker news aren't as concerned as I feel about the current situation. Whether you own crypto or not you would be crazy to hold bonds or debt as an investment over precious metals with the state of the world being what it is.
Let's see. Are you holding these "precious metals" in your hardened safe or it's just numbers in any of these brokers?
I personally purchase and hold precious metals at home and then play miner stocks and precious metal etf options for more exposure.