One issue with the existing decentralized exchange (dex) ecosystem is the limited offerings that are available to participants. Confined to the ERC20 world, traders must transition to a centralized service if they would like to gain access to cross chain assets (ETH/BTC for example). Additionally, there is no path for anyone to gain exposure from crypto to real world assets, like AAPL/USDT, even from a centralized service. Usually, traders are looking to gain price exposure to an asset and do not care about actually taking custody of that asset. For instance, if a trader thinks bitcoin will rise in value and wants to make a profit, they don’t actually need or perhaps even want to hold bitcoin, rather just earn profit from its price appreciation.
https://medium.com/market-protocol/expanding-the-world-of-products-available-on-decentralized-exchanges-2d908667268d