Although Tether's purpose has largely been to avoid regulation, and participate in cryptocurrency speculation, a stablecoin would be superior for actual commerce. Bitcoin has failed for commerce, to some extent because of instability and speculation.
Being able to use something equivalent to cash to transact digitally, with client-side security seems like a desirable technology to me.
Superior to bitcoin, surely, but no superior to dollars. I have absolutely no difficulty with using my dollars to pay for anything I want.
The biggest reason one might not want to use dollars is to conceal one's identity, and while I admit that there exist valid uses for that, most of the market for anonymous commerce is illegal activity.
The currency exchange rate is a minor price to pay for such a convenience.
Meanwhile with <insert literally any cryptocurrency here> it’s just a simple <convoluted 20-step process not even guaranteed to work and with no consumer protection>.