3 key reasons:
1. Cost of development
Apple and Google have invested, and continue to spend millions of dollars to design, develop, deploy and manage their wallet applications. Because they are ‘built-in’ to the phone they access a lower level of capabilities that third party developer s cannot access.
2. Installation base
Apple Wallet is installed as standard on all iPhones and iPods running iOS6 or above (>99.9% of all iOS devices). It is also a standard application on all Apple Watches. Google Wallet is installed as a standard app on many Android devices, and the plan is to make it a native application on all Android devices.
3. Consumer preference
Smartphone owners prefer to store and manage wallet content in their wallet application (as they prefer to store and manage email in their native email application, or browse the web in their native browser application)
Passes are a digital representation of information that might otherwise be printed on pieces of paper or plastic. They let users take actions in the physical world. For example, obtain a discount at a gas station, gain access to an exclusive event, redeem a free item, board a plane, collect points when paying for goods in a department store.
Passes can contain images and a barcode, and you can update passes at any time. Users view and manage their passes using the Wallet app of their choice. (i.e. Apple Wallet and Google Wallet)
The PassKit framework also provides an interface for apps to interact with passes. Companion apps should not duplicate the functionality of the Wallet app, rather they should enrich the user experience by doing things that Wallet can’t do, such as letting the user update their home address, or redeem points and then updating the pass. Passes need to be useful even if the user doesn’t have your app installed.
Even if you’re not creating watch-specific apps, users can add any passes you create to their Apple Watch.
Passes let your users take actions in the real world, so accessing them needs to be easy and fast. Wallet applications makes relevant passes immediately accessible by integrating them with the lock screen. To take advantage of this feature, you simply add information about where and when the member’s pass is relevant (note that this can be the same or different information for each customer).
A pass’s relevancy can be based either on the time or the place where the user can actually utilise it. You simply provide a point in time and points in space via PassKit. The Wallet application then determines whether the pass should appear on the smartphone lock screen based on these settings. It calculates when the user is close enough to the specified time and locations based on the pass stored in the wallet application. You therefore don’t need to program any of this logic in your application.
Note that relevance information is passive; it helps users find passes when they need them by putting relevant passes right on the lock screen. It doesn’t present alerts or post notifications. This is in contrast to the notification posted when a pass updates (e.g. more rewards points are collected, or points are redeemed).