I think the very safe wallet to use is a blockhain wallet and we also need to store it offline. I beleive that offline wallet is more safe because there is no way to hacker to trace it. We also need to be more careful on our private keys because there are so many people that lost thier asset becaue of not taking good care of thier private keys.
Blockchain wallet had some problems with phishing. You will never be sure of safety if someone else holds your private keys and that includes exchanges and online wallets.
Man it looks like you have paranoia. Use only one hardware wallet and do not worry 
... Or hold your bitcoins a large exchange that returns funds to users in the case of a hack, but a cold wallet is still safer
... Or hold your bitcoins a large exchange that returns funds to users in the case of a hack, but a cold wallet is still saferYou can never be too careful. A hardware wallet is great but it's also good to have a backup in case it gets damaged and remember to divide your money and keep them in different places.