Ultimately this is because central banks are in the driver's seat for asset prices these days. It's been trending that way since the Greenspan Put in the 90's. The economic fundamentals matter, but not as much as the monetary policy backdrop; after all, if there's more cash chasing the same number of shares, it can't help but drive up stock prices. Similarly, low borrowing rates reduce the equity risk premium, drive up growth valuations, etc.
So really, the real test for crypto is when the monetary policy regime shifts. But to be honest with you, I don't see that happening. Maybe inflation finally forces the issue -- but then there's the fact that inflation will drive flight to alternative assets anyway.
Probably because the govt/Fed is printing more money.
Well, there was a recession just last year and the stock market / BTC market went crazy.
The real question is what happens in the next market downturn (specifically the cryptocoin market downturn, since these "stablecoins" look like they're "stable" only because of assumptions underlying the cryptocoin markets). The cryptocoin markets don't necessarily match up with the general economy.