Product teams can refer to their customer journey maps for various reasons. In fact, different roles have different uses for them - product designers can use them to identify and then solve customer/user problems, UX designers can use them to design smooth customer/user experiences, marketers can use them to plan effective marketing campaigns, and so on.
My favorite customer journey map example is from Spotify. Although it doesn't depict the entire customer journey like most customer journey maps do, it's clean and easy to understand. The objective was to increase the number of users sharing music using Spotify, thus the purpose of the customer journey map was to learn where in the customer journey users would want to be able to do so.
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