If bitcoin is not as good as USDT or Tether, then bitcoin will not occupy the top position to date. The increase and decrease of other bitcoins and crypto coins is like a wheel, it's spinning. Even if bitcoin experiences future falls and failures, it will also happen to all altcoins. This will be like a domino effect because bitcoin is a role model for all coins.
You are right in part, the domino effect will only be raised from the panic by the people. Only because of this, the domino effect will begin (selling for any amount).
But that the tokens will fall I do not think that this will happen, since most coins work on the erc20 standard