There are standards for everything, when you are in a confusion you should always look for those.

Here is apple's standards: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/

Here is Android's standards: https://developer.android.com/studio/write/image-asset-studio

There are standards for everything, when you are in a confusion you should always look for those.

iOS's standards: https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/app-icon/

Android's standards: https://developer.android.com/studio/write/image-asset-studio