Will deleting Google app stop 2-factor authentication on iPhone?

Deleting the Google app from your device will not reset or disable two-step verification on your Google account. Two-Step verification is a security feature tied to your Google account itself, not to any specific app. Even if you uninstall the Google app, 2 Step Verification will remain active, and you will still be required to verify your identity using your chosen second step—such as an authentication app, text message, backup code, or hardware key—when signing in from a new device or location.

Removing anything Google will not turn off Two Factor Authentication once set on an iPhone. They are completely unrelated.

Actually, if you delete the app, you will have no way to authenticate the accounts that have been set up with the Google authenticator, and that would cause a bigger headache.

As far as the Apple account: there is NO way to turn off 2 factor; it is an Apple requirement. And Apple does NOT use Google authenticator. It authenticates via a "trusted device" (usually a computer, a second iPhone, iPad, etc) or by sending you a code to a trusted phone number.

Hope this helps.

Will deleting Google app stop 2-factor authentication on iPhone?

No

Your next question might be can you remove 2 Factor on the iPhone you are trying to use.

No

Re: “… unlike Apple, Google lets you recover from the enormous error of blocking your life if someone confiscates your phone …”

Sounds as if you might also be facing challenges w/ “Apple Account” access ???

Did your father possibly pre-designate an Apple Account Legacy Contact? If so:

Request access to an Apple Account as a Legacy Contact - Apple Support

If not see:

How to request access to a deceased family member’s Apple Account - Apple Support