It would be fine if the footage was end-to-end encrypted, meaning you need to transfer the encryption/decryption keys from device to camera, and then manually between all devices that should have access to the decrypted footage.

Camera would only ever send out encrypted footage, and thus it would be insufficient to have access to the cloud account if you want to view the footage - you would need both access to the account (to obtain the encrypted data) and the decryption key (to actually decrypt it). The decryption key must never reach any 3rd party servers and can only be manually transferred between devices that should have access.