It doesnât matter. A backup is different.
Syncing means the contacts are forwarded to other devices using the same account automatically. When you add a new contact or remove one of those youâve saved, this will also happen on all other devices using the same account, without backup.
It looks like youâve set up your Gmail account for the built in (Appleâs) Mail app, which means the contacts connected to your Gmail account will appear on your iPhone in the built in app. As soon as you remove the Gmail app in Settings - Mail - Accounts, these contacts will also disappear in your contact list.
Weâre suggesting to either export the contacts from this Gmail account to iCloud, or to keep the Gmail account installed in your settings, and enable Contacts only. That way, the built in Mail app doesnât show your Gmail account, but the contacts are still in your list.