If I am encrypting the content on an external hard drive with VeraCrypt should I also encrypt the hard drive?

Like it says, if I'm encrypting the actual data (think they call it a volume) on an external hard drive, should I also encrypt the hard drive? Is this overkill / bad practice, etc.? My plan is to move a backup copy of the encrypted file onto Dropbox. I'm new to the encryption world so just now learning all of this.

bad call data drive encrypt etc external hard hard drive practice privacy