But also Biftinex/Tether benefit if people lock up their USDT into earning schemes rather than trying to redeem them for fiat. It reduces withdrawal pressure and allows Tether to keep the game going.
(This is assuming the common theories that Tether is unbacked/poorly backed are true. In a ponzi, managing withdrawals is paramount, and all the crypto high yield earning on stablecoins provides a way to discourage withdrawals)
I haven’t thought through the trading aspect though or why that would be subsidized. I guess it does soak up USDT as well.
Edit: a couple other facts came forward.
Deversifi was originally called Ethfinex, a Bitfinex spinoff
The miner that got the fee is owned by Christopher Harborne, Bitfinex shareholder: https://protos.com/bitfinex-tether-digfinex-shareholder-harb...