Bitcoin has a higher potential, and that also matters. If we consider Bitcoin merely as an asset that one holds and then sells for profit, it's different from a valuable rock because it's way easier to buy/sell and hodl due to it being digital, but these differences can be called non-essential. But Bitcoin is something you can send to others, no matter where they are, and you can do it without intermediaries. What's a pretty cool feature that rocks lack. Also, one can buy things with Bitcoin, and there are more and more places all over the world that allow to do that. Finally, unlike a rock, Bitcoin cannot be faked, so it's safer.