Because at times you want to hand a piece of paper to somebody. The Opendime / Satodime have a real cost to them and as I found out can fail.
The benefit of the OpenDime though is that the receiver can be pretty confident you don't know the private key. Handing someone a paper wallet is incredibly insecure for the receiver. If I was accepting a paper wallet from someone it would have to be someone I trusted enough not to scam me, and in such a case I would trust them enough if they said "Give me your address later and I'll send you what I owe you."
Interesting approach. I've never sweeped a paper pallet, I've imported it if needed.
It's fine to import your own paper wallet to an airgapped device, but if the paper wallet was given to you as per Dave's example, then you should absolutely sweep it so the other party can't steal the funds and so you don't have to trust how securely they created the paper wallet in the first place.