The reason the dollar is a currency is because of the existence of a force (in this case, the Fed) that can tamp down speculation and deflation. Cryptocurrency doesn't have this, and that is its central failing.
Speculation is a good thing, it's a form of entrepreneurship.
Example of historic deflation: https://en.m.wikipedia.org/wiki/The_Great_Deflation
Stake: 0.05 BTC, 1.2 ETH
But they don't. Not if it's things they need now, like food, or want now: electronics have been deflationary for the last 70 years or so -- when you bought the device you typed your comment on, you knew full well that a year later you would get a better one for cheaper, and yet you didn't hoard your currency. Trade in electronics doesn't seem to be grinding to a halt.
Useless crap people don't actually need? Sure, that might suffer from deflation. But ideally the world economy wouldn't be founded on useless crap that people don't actually need.
Stake: Held some Bitcoin ca. 2011-2021, just enough to buy a nice (not fancy) apartment slightly below market price. Divested now. Miniscule amounts of Monero and Tezos, basically written off.
>prices of goods, materials and labor decreased, although at a low rate of less than 2% annually
you can deal with. Crypto style 50% drop in months type deflation would make debts in that currency unpayable.