It's true that current circulation coins have very little value as metal scrap. The largest coin you're ever likely to encounter in circulation is the Kennedy half dollar. Since 1971, they are made of a copper core with a copper/nickel cladding layer, just like current dimes and quarters are. It's current melt value is approximately $0.09.
But, when yo speak about "true value," consider that anything you're trying to attach a dollar value to, you're measuring its value in terms of dollars. A dollar today really is little more than a bit that's set in a computer somewhere. Why do we give that any value at all?
The answer is that the USD, along with most, if not all, current world currencies, is essentially an "economy token." By that I mean the USD is literally just a way to keep score, i.e. to tell how much you're winning at the game of capitalism.
This seems like neither a good thing nor a bad thing. It just is what it is.
Interestingly, according to https://sdbullion.com/blog/how-much-silver-gold-is-there there are about 6e9 ozt gold and 5e10 ozt silver above ground right now. At today's current spot prices of $1789.55 for gold per ozt and $22.78 per ozt, that works out to about 1.2e13 USD worth, which, if we made all money either out of or backed by gold and silver in a 1:1 ratio, would literally be all the money in the world.
