Everything is a balance of risk and convenience. Chance of losing your onsite backups vs having an issue with your offsite. It would probably be safer to store an encrypted copy on an external drive and keep it in a safe deposit box but that is definitely inconvenient to update. There are cloud services that offer zero knowledge encryption on the server side but ultimately there's always some client program that needs to be able to decrypt the data. This is what I do for my cloud backups but it really depends on you trusting the client application. Personally, I'm not too concerned.