As far as I know the new banners are a fixture of iOS 15. I can think of two ways to get rid of them and one potential workaround you probably won't like…
  • Switch to a different cellular phone from another manufacturer
  • Revert back to iOS 14 (I have no idea how you would do that)
  • In Settings > Phone > Notifications turn Announce Settings ON. (Siri would then verbally announce your phone calls and instead of looking for the stop or answer icons you just say, "hang up" or "answer". In this unique instance "Hey Siri" is not required.)

Last edited by joemikeb; 11/15/21 11:00 PM. Reason: ending parenthesis
If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein