If every piece of paper was as valuable, you could print numbers on paper and pay your dinner with it.

If every coin was as valuable, copying Bitcoin 1:1 and mining it to yourself would make you immensely wealthy.

It is called "legitimacy" and it's hard to get. The U.S. barely manages to retain theirs by having a 51% attack on the world's military. With garagecoins, it is harder.

ADD: comparing market caps with current number of coins is misleading. The total number (or perhaps the number at the point when yearly inflation goes <2%) is more important.