I'm not sure why, but most wallets do not have an address feature. Having a one stop shop for all your wallets just make the entire use case easier, and I believe it's that would help attract new crypto users to support the industry and it's movement. An address book like Digital Names saved me a lot of time to pull up saved files and find the needed address. Oh, and this is not limited to one specific blockchain, so you can have different wallet address like BTC, ETH, STEEM, ETC, and so on...
Use Digital names, because it helps you to easy remember your aliases in public addresses. It will help you to any transaction to easily pay someone using your account. It will also help you to secure your wallet address to prevent loss. Digital names will help you personally to make faster and quality transactions anytime.