There are people who use computers, like Macs and PCs. If you click on an address in an Address Book entry on a Mac, it points to Google Maps.
Also, at some point, if a person logs into iCloud on a Windows or Linux PC and clicks on an address in the Address Book section, it should again open a browser page for Apple Maps, not Google Maps.
Moreover, business owners might want a web interface to correct/update imagery, business information (hours of operation, telephone, URL, etc.).
A printable map might come in handy from time to time.
Lots of reasons why a web interface for Apple Maps would be useful if you can see the forest for the trees.
Apparently, you cannot.