Market cap is the wrong metric to use. Tether is debt. Its entire market cap is redeemable in USD. It’s not possible to redeem the market cap of e.g. Bitcoin.
Not really, Tether’s terms don’t provide much in the way of redeemability. It’s quite probable that most of the Tethers already minted never had an actual dollar behind them anyway.
A Tether is redeemable. The terms say you may experience a delay, due to liquidity issues. But it’s still redeemable.
Issuing a token, and claiming it will always be worth $1, simply by hoping that someone, somewhere will buy them for $1 is fraud.