The most likely theory at this point is that most of it is FTX-style IOUs from other crypto companies marked at absurd pre -crypto winter valuations, which will collapse like a house of cards the instant they are touched or even exposed to light.
what's your source for that? Tether itself admitted that isn't true: https://cointelegraph.com/news/tether-to-reduce-secured-loan...
They announced they are curbing this activity so maybe it brought them more loss than gain?
They still probably didn't leak mucj tether this way. But I now see that it's not that 66 bln of dollars changed hands, but most of it in crypto valued at bull market prices. So if people wanted to cash out into dollars they would probably collapse. But why would people want to cash out into dollars en masse and pay tax on that?
And if they want to cash out into crypto there's no problem becuse the crypto is cheap now so tether doesn't need to give away much for each USDT they redeem.
Because they think Tether will collapse. It will happen slowly, then all at once.
Because they see it as a likely loss, and would rather get some return than nothing. A taxable gain is always better than a loss.
Even if the gains were in other crypto and are now being cashed out via Tether to $USD, it's better to realize those gains in $USD and pay 0%, 15%, or 20% capital gains taxes (depending on your income bracket), rather than lose it all due to Tether becoming worthless. Manageable but certain cost vs unpredictable likely total loss.
Also the question is, do people really want to call them on their promises. That's another thing noone would benefit from.