Back in 2019, Google said it was "sunsetting" AdSense for Android and iOS, asking users to check their online ad revenue on the website. That said, the native Android app continued to work fine until this week, but it's completely dead now.
In the past few days, AdSense for iPhone and iPad has stopped working. It's unfortunate that Google didn't include a clear exclusion notice.
More importantly, you get an "error occurred, try again later" toast message. No troubleshooting steps, including clearing the cache/storage, resolve this empty data issue. Meanwhile, the app was removed from both app stores in April of 2020, so you can't delete and reinstall.
This shutdown was originally supposed to happen two years ago, but was delayed in normal Google fashion. The company also said that AdSense for Android and iOS will be removed "in the coming months" for 2019, but the app continued to function normally until this week. The only notice in the notifications was:
Adsense works fine on the web and is a lot more modern, but lacks you homescreen widgets and convenient icons. Unfortunately, there's no Progressive Web App in Chrome with the standard "Add to Home Screen" option that creates a shortcut that retains the regular browser UI.
In the meantime, Adsense for iOS is still in the works today, but Google will likely make any changes to Apple's platform on Android in the near future.