Well, the dollar used to be backed by gold which gave it a limited supply. Un-tethering the dollar to gold gave it an umlimited supply.
The dollar was fine up until the supply became unlimited. Bitcoin not only has a limited supply, but a controlled supply which is predictable and finally capped after ~100 years. https://en.bitcoin.it/wiki/Controlled_supply
I kind of like it better than gold with the questionable supply, what if we find gold on other planets, or new supply somewhere here. Not to mention the unknown amounts already out in circulation.
EDIT: A new form of precious resource, the first kind that's digital. welcome to the future.