Safe if you can make sure the wallet is safe on the place that no one can found it!
But if you lost it on somewhere, you lost you're asset on it. So stil need aware from you to make sure you won't lost it in the future. Good luck for your hardware wallet
That's not right. It doesn't matter if you lose the device as long as you've got your recovery seed which you should store offline in a safe place where it can't get lost.
Hardware wallet is safe but not absolutely. Paper offline wallet is safer. But the strongest level of security can give only brain wallet
Why would writing your private key on a piece of paper or just memorizing it be safer than a hardware-wallet?
a) For both methods you'll have to generate your private-key in a secure offline environment that has never and will never be connected to the internet otherwise you're already decreasing the security while generating the wallet
b)
You'll have to sign your transactions in an offline environment - as soon as you're using your private-key on any online device you risk that it might be grabbed by malware if the device is infected
So
if you're doing it right the security might be comparable to a hardware-wallet and for ETH/ERC20-Tokens it's quite easy to do but if you're doing it wrong (for example using the private-key in an online environment) you might decrease your security to the level of just using the
unencrypted private-key in an online environment (which for most people is not a big problem but as soon as you're getting infected with malware, your wallet might get "hacked").
Hardware-wallets on the other automatically isolate the private-key from the internet and there's no way of accidentally exposing it by a user error except if you're storing your recovery seed on your PC (obviously don't do that! Store it offline in a safe place where nobody else can access it and it doesn't get lost in case you lose your device so you can still get access to your funds)