I'm not very familiar with how treasuries get bought/sold/transferred between parties. But they seem pretty cash-equivalent, Uncle Sam will sell as much as you want, and your profit margin is baked into it.
This is better! But a couple issues. One, this means the U.S. Treasury has an open book into your in and outflows. Not sure that's Tether's vibe. Two, you've limited yourself to people who can transfer Treasuries. Given Tether doesn't provide consumer redemption, this isn't a huge issue. But transferring Treasuries takes more financial savvy than wiring cash, and that savvy is likely to ask for their interest (as is common in collateral arrangements).
It's relevant to the difficulty of launching and operating a U.S. dollar stablecoin.
What I meant by saying 'it seems easy on paper' is that the need to be profitable shouldn't force you to make decisions which eventually lead your treasury to not being valuable enough to back the minted coins.
Also: Perhaps I don't understand how tether works, but I don't see why they need to be liable for holding customer funds. Why do they need a deposit/withdrawal process at all? Can't they just do the following?
IF USDT on open markets is <$1 THEN buy coins and burn them
IF USDT on open markets is >$1 THEN mint coins and sell them
And then they can do whatever they want with the treasury, no? Store it in banks or buy US treasury bonds, etc. Just don't lose it.
Mechanically, what does this mean? When someone buys Tether from you, to which bank account do you have them wire the money? By the way, your suggestion is a reasonable leap. But it still involves handling U.S. dollars, and now you've added a new regulated area (wealth management).
It's easy to imagine the transgressions starting small. Say you have someone ready to wire you $100mm. You don't yet have a bank account, but you're working on it. Do you tell them to pound sand? Or do you temporarily use a side account, to hold the funds until the main one is ready?