Yes, but we have phone numbers. Phones have been around long enough that you don't need to draw a picture of a phone next to a phone number for people to understand it. That isn't true for a public key for most people. Some keys can look similar and provide little context as to what they are for. For example, my username on most social was @mattkwarren. Cool. Where? Most people will recognize the Bitcoin logo more easily than a Bitcoin address. Yet Bitcoin is also a protocol.