A paper wallet, is a piece of paper where you write your private keys, which must be imported, allowing a user to validate the entire operation.
- Immune to computer viruses that steal from software wallets.
- Harder to use.
It's not. Paper wallets are still as susceptible to theft as a normal desktop wallet. The only difference it has is that the wallet itself is stored on paper and thus its exposure is lesser but their risk is roughly the same. You would still have to spend it securely and its to import it on a clean computer or on a computer that has never been online. It's not secure if its not generated and spent securely.
Paper wallets are harder, sure. But they aren't that impossible. It's not hard to use it on a client, say Electrum. The importing and spending of it is rather fast.