This idea is just like fiat paper money. You have to put your trust in the person printing these paper wallet notes. What’s to stop people printing fake addresses on these paper notes. Would you trust someone enough to send them some BTC and only get a piece of paper back? What happens after you buy such a note and turns out the so called wallet has nothing in there? I think this is a terrible idea.

Why don’t you send me 500 BTC right now, I’ll give you a piece of paper in return, and don’t worry you can trust me, i garauntee there’s 500 BTC in this wallet on this piece of paper. sarcasm