Why is there no way to move the data automatically from android to iOS after the iPhone has been set up?

Did you try to use the Move to iOS app in the Google Play store? Move from Android to iPhone, iPad, or iPod touch - Apple Support That is how one moves to iOS from Android. However, once you have set up the iPhone, that cannot be used.

If you are looking to move specific content, much can be synced, such as Google Contacts, Calendar, but not all content. That has to be done at the beginning with the app.

You can set the device up all over again if that will be faster for you. It sounds like maybe you got a new device and set it up not knowing this solution worked this way, so maybe backing up the smaller amount of iPhone stuff onto a computer or cloud drive like google drive would be faster.

To get it back to 0 to set up anew, the fastest way is detailed here: https://support.apple.com/en-us/HT201351

good luck!

Here's what gets transferred: contacts, message history, camera photos and videos, web bookmarks, mail accounts, and calendars. If they're available on both Google Play and the App Store, some of your free apps will also transfer. After the transfer completes, you can download any free apps that were matched from the App Store.