I came to this forum because I am having the same problem using the local backup to Google drive and it has been over a year since the original poster brought this to the forum.

It seems that the correct and honest answer from QBO should be that you cannot create a backup that will appear anywhere that you can see the file, whether it be Dropbox or Google Drive.

Instead you will be forced to export the data and manually import it into the different QB platform.

In essence QB is forcing its customers to continue paying them a monthly fee to access their accounting data in QBO. 

My client needs their data saved for future lookup capabilities and this is just in case it is necessary.. There is no reason this company cannot be backed up and opened in QB Desktop Pro, other than the fact that QB won't allow it.

If this isn't an example of corporate greed, I don't know what is.