The Bitfinex's stablecoin Tether (USDT) is slowing migrating toward Ethereum as an ERC20 from the Bitcoin Layer2 OMNI.
That was a great choice, Ethereum is perfect to handle tokens transfer and your customers can now benefit from faster and better transactions.
USDT is a giant, (1.9B$ as for now on Ethereum), it's the main stablecoins for traders, IMHO DAI is more decentralized but I won't fight the market on this.
but that giant is representing 15 to 25% of the block space on Ethereum, increasing the Gas Limit is an option but will have consequences on the size of the blockchain and the uncle rate.
Tether and CEX are playing fair and traders are paying market fees for the service of using Ethereum, as of Today almost half a million buck has been paid to miners to mainly move USDTs from a CEX to another CEX (HuoBI, Binance, Poloniex mainly)
Dear CEXs, banking on Ethereum tech, you can provide a better, faster and cheaper service to your users by using a Layer2 solution.
By definition, y'all are centralized, using a sidechain such as POA network (xDAI chain) or a similar architecture would be much more effective and everybody wins as it'll be less demand for block space and lower gas fees for everyone.
I'm pretty sure the main actors of the ecosystem would be more than happy to help you #BUIDL this.
Be cool, use the best tools Ethereum can provide for the benefit of the ecosystem and your users.