If I back up to iCloud, do I need an additional external hard drive backup for my MacBook Pro?

Wever wrote:

If I back up to iCloud, do I need an additional external hard drive backup?

If you value your user data. Do not wait for a catastrophic failure or data loss to get the backup religion...

3-2-1 Backup Strategy: three copies of your data, two different methods, and one offsite.

More than one device, more than one backup methodology.

—Back up your Mac Back up your Mac with Time Machine - Apple Support

iCloud is more of a sync service not backup.

Manage your iCloud storage

Manage your iCloud storage - Apple Support

iCloud+ may well offer server space for more of a backup option

Upgrade to iCloud+

Upgrade to iCloud+ - Apple Support

iCloud+ plans and pricing

iCloud+ plans and pricing - Apple Support

Wever wrote:

Thank you. My concern with an external hard drive (G-Drive) is it being stolen and hacked. Is it protected by the same password as my MacBook Pro?

ref:

Encrypt and protect a storage device with a password in Disk ...