Fair enough point, but I still would be hesitant to put all my eggs in one basket, no matter what my age. Of course, if you are real young and barely just living on your own (moving out of the parent house or even living with parents and in the early stages of building your wealth), then in those cases, you usually do start with just investing in one thing while you are building your portfolio, and then you might start to expand out with the passage of time. If you only have one investment because you are just starting to invest, then probably in those kinds of circumstances, you might start out with bitcoin... perhaps? Those are somewhat individually tailored decisions concerning how diversified any person needs to be in terms of cash flow and projected expenses, too.
It also depends on your income. I'm not 20 but still at the start of my career, without a good diploma, so not a great salary. Most of my savings go towards my company's stock, as it's making a matching contribution, it's a safe bet I can't overlook. I was in the stock market but sold everything as it became scary, two years later it has basically not moved (French stock market), so I just lost some dividends, but got peace of mind. Overall I'm 30% company stock, 30% cash, 40% BTC, with BTC's share quite volatile obviously. At current prices I couldn't even buy 1BTC/year so not really worth it, better keep cash and buy when it's lower. I want to put the company stock and some/most of the cash towards a home with a small mortgage on top, after that I might put more money towards BTC, but not even sure, I'd like some land, maybe a bit of forest.
You seem to be describing Armageddon-like scenarios in which gold might prosper in such a way that is appreciating 10x or more from current value, and yeah, I agree that we should not be making the bulk of our investment decisions and/or allocations based on such unlikely scenarios, but we might chose to make 1% to 10% of our investment choices based on such scenarios, especially if we assign them a high probability (such as 10%, which seems a bit high to me, but might seem reasonable to some of the Armageddon nutjobs out there, such as roach and like-thinking acolytes of similar dumbass mindsets)
In that case you also need physical gold, stashed at home. An ETF or whatever is useless. Stashing at home has its own downsides.
Seriously consider selling part of your company stock for other stocks
Right now, if your company goes under, you lose your job and your investment at the same time.
For me, that risk is too concentrated.
