The reason for Android's Notification system being better than iOS, is solely due to the ability to turn off individual aspects of an application's notifications.
Google, the poor multi-billion dollar scrappy startup that maintains Android, made a payment app that has one notification setting, "Google Pay". So all the ads, promotions, everything.
3rd party apps like PhonePe & Paytm have a better system.
You do realize Google Pay is not maintained by the same set of people who maintain android. The 1 notification option is pathetic, but you get what you get. The android apps are not maintained, so they fit and follow all of android’s guidelines. If they were. You would be seeing material you theming in most of them where applicable.