Can someone with more knowledge of finances and crypto explain this to me?

From the outside Tether always seemed like a scam. The characters involved scream scam and a stablecoin seems very easy to siphon off money from. So long as you assume that the number of Tether dollars held never drops by 80% then you can just pocket the 20% (of the giant number) and pay off withdrawals with new inflows. Due to the lack of regulation this seems like it would be easy to pull off - at least for awhile.

Is there reason to believe this isn't what's happening?