You can't eat paper currency, either.
OK, that is missing the point. You also can't eat a knife, you can't eat a shovel, you can't eat a bag of fertilizer, you can't eat a bow & arrow, and you can't eat a Costco membership card. But sometimes those objects might be quite valuable in attempting to obtain food, and sometimes they might be totally useless.
The important analysis to be done is, "Under what circumstances will paper money become worthless, credit cards useless, investment vehicles fail, banks close, AND society will converge on a functioning alternate store of value based on the rarity of certain precious metals. Sounds like a TEOTWAWKI situation to me.
You calculate the odds of that situation (which are not zero, true), compare that against the odds of other situations that you might want to prepare for, and calculate what you might do about it, and then make your bet. What scenarios are you actually defending against, and what is the likelihood that your proposed defense is going to work?
Everyone makes their own decisions. And who, actually, is going to want to trade something practical for your silver coin? For me, I'd rather store canned goods than silver dollars. Even in a disaster situation, I think that would be a better medium for barter.
Now it is true that there are entirely rational financial advisors who suggest that a small position in precious metals (say %5) can serve as a useful inflation hedge in a balanced portfolio. They almost never suggest taking physical possession however, but gaining exposure via suitable financial instruments (e.g., gold mining stocks).
Finally, there is the hobby aspect, which I am the last one in the world to deny. I have no rational survival justification whatsoever for my 20 flashlights, 20 pocket knives, or dozen different cell phone chargers. I just like 'em. If you like gold or silver coins, that is a perfect reason to own them. I used to collect stamps in my day, I liked those too. But they weren't a practical financial survival tool.