Bitcoin market cap: $8.3 billion
Uber the taxi app: $18+ billion
Is it just me, or something is wrong with this picture

Someone already answered your question, every product is worth as much as the market is willing to pay for it. And by the way you shouldnt be comparing Bitcoin to Uber, Uber is a huge company and available in lots of countries and even well trusted by investors around the world, whereas in Bitcoin investors are still scared of investing in it and lot of people are doubting it. But this is just the beginning.