Problem Deleting Apps on Mojave 10.14.6 Downgraded from Big Sur

After downgrading from Big Sur to Mojave successfully, there are apps in Applications folder which I am not allowed to delete since they are "required by MacOS," even though they display an error message if I try to open them. Examples are "News.app" and "Voice Memos.app." Also their preference.plists cannot be deleted for the same displayed reason.

Is there a way to get rid of these non-functional "required by MacOS" apps apparently carried over from Big Sur?

Author: wstrohm