Why is my iPhone forcing me to set up ApplePay ?

Please follow this path,

iPhone > Settings > Notifications > Wallet > Allow Notifications > turn off

This will stop all notifications from your Wallet app. Should you decide to setup you wallet in the future, you’ll want to enable notifications. Notifications can notify you of possible fraudulent charges, payment dates etc.

Wallet - Apple

You are not being forced. What is the real issue, is it frequency of notifications or what exactly?