Take a trivial example - a person with no debts. You have to concede such people do exist in the world.
They are by definition not insolvent, and cannot be. Even if the currency completely collapsed and USD had zero value this would not make them insolvent because they have o debt and therefore no financial obligations.
Insolvent companies usually fail anyway. It's better to catch them early before they can make things even worse for their customers and investors.
But it begs the question, is Tether meant to be a viable stablecoin, or is it a fractional reserve piggy bank for the Tether owners to earn interest from?
Clearly they're running it like the latter. Why would the crypto industry consolidate on something scammy like that?
Ideally a stablecoin would be non-profit and run strictly for quality purposes with audits etc. Why would you ever need more than one? The desire to skim some off the top is far too pervasive in crypto