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The disadvantage of the first two points can be compensated by applying information to metal, instead of paper, and then the problem of susceptibility to fire and water is eliminated. Also, if it is chasing and engraving on metal, then the problem with print fading is also eliminated. You can also apply a method such as galvanization, for example.
-snip-If the material is no longer paper and replaces it with metal, then I think the name is no longer a paper wallet.
There are still many other risks that may arise from using a paper wallet beside the ones I mentioned above.
I guess these paper wallets is just for people that are very careful on their investment the one that is going to buy put it in the paper wallet and forget about it.
If the goal is for long-term investment, I don't recommend using a paper wallet, as some of the disadvantages of a paper wallet have been mentioned above.