Let's counter his arguments: how often has a paper wallet leaked millions of customer addresses?
Not really a fair comparison. How could a paper do that?
Exactly, that's my point
Consider this scenario:
You said you have a printer without WIFI. Maybe you bought it with cash, maybe with a credit card that shows your real name. That information is stored somewhere on a server. The shop gets hacked and the data gets leaked. Does that make your product (the printer) worse? Would you stop using it and throw it away?
Everybody has a printer, nobody cares about it, and nobody is going to hit you on the head with a $5 wrench to ask you about your printer. But just in case, you can pick one up at a store, wear a mask inside, and pay in cash.
Some printers have features that do not work well with printing confidential information. For example, some printers will save the last
n pages it has printed so the user can easily reprint something they spilled coffee on. Sure, you can probably disable this feature, but it is one more thing you need to worry about.
Should someone who knows how to make them secure, understands the risks & vulnerabilities and such use them if they want to? 100% yes.
The thing about paper wallets is that it really never makes logical sense to use one. In all cases, the potential risks involved in using a paper wallet include all risks involved in using a wallet stored in digital format and include additional risks not involved in storing a wallet in digital format.
For example, when you generate your private keys, you must rely upon the RNG of your OS. This is true regardless of whether you are creating a paper wallet or a wallet that will be stored on a USB drive. If you are creating a paper wallet, you must expose your private key to any "eyes" (including cameras) that can see in the room you are in. If you are creating a wallet that will be stored on a USB drive, you never need to expose the private keys to "eyes looking in the room".
While you are storing your paper wallet, if someone is able to access your paper wallet, they can ~instantly make a copy of the paper wallet with a camera (they can also take the actual paper wallet, however there may be some situations in which an adversary can see the paper wallet, but cannot remove it). With a wallet stored on a USB drive, an adversary would need to connect the USB drive to a computer, or other equipment in order to make a copy (or they can remove it, if possible). If there is any encryption applied to a paper wallet, the exact same encryption can be applied to a wallet being stored on a USB drive.
When you spend any coin stored on a paper wallet, you again will need to expose the private keys to the "eyes looking in the room", and again this is not the case for a wallet being stored on a USB drive.
If you were to replace "USB drive" with "Hardware Wallet" above, you would have incrementally greater security because HW wallets generally have a "cool-down" period in between unsuccessful attempts to use the HW wallet.