If I make a backup to an encrypted Azure blob do I also need the local encryption? Or is it good to go without encryption? Well if someone get’s my accesskey to the blob they will be able to read it tough? So I think I still will use the local encryption.
Local encryption is certainly the best option. Just let duplicati generate a strong password for you, save it in a secure location (e.g. a password manager) and you can rest assured that your data will be extremely safe and secure.