Keep in mind it's not a binary choice. You can exchange anywhere between 0 % and 100 % of your savings for some other asset class, like stocks. An extreme position in either direction is probably a mistake, but what about 20 %? 30 %?

The idea is not to get rich quick, nor is it to avoid any risk (because both are statistically impossible.)

The idea is to limit how much a crash of any type hurts, by having some savings also in other types of assets.

So for example, if your savings are $100 and you buy stocks for $30 of that, and the stock market crashes so you're down to $10 in stocks, now you only have $80 in savings. But you can use your cash savings to bootstrap your stock position back to 30 % again. If the market recovers, you get an outsize benefit from that.

(Similarly, if there should be some sort of dollar crash, you can probably use your stock market savings to bootstrap your dollar position again, putting you in a good position for recovery.)

Bravo. Peace of mind is an indirect cost of investment. I've met a brilliant head of engineering, that told me "I've sold all my stocks/coins so I can stop looking at my phone and reading articles, and I can really focus on what matters". Not having state bonds that allow people face inflation, has a HUge indirect cost: having offices full of nerds looking at stock/coin exchanges. How much human valuable time is now lost on that?

In a place where people will want to buy houses for the next 30 years, at an inflation-adjusted price which preserves the value of your investment,

and assumes you've already bought the house or can do so in the near future while mortgage rates remain low, while the struggle is that the cost to get into the market is rising at crazy multiples (30% yoy?)

and assuming enough economic stability that you can be sure to make the payment even if your job moves.

People thought real estate was a can't lose investment back in the run up to 2008 as well. While real estate can be a good investment for many people, a lot of places are well into bubble territory (Canada, Australia, and China come to mind).