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

im guessing that your questioning how come uber the taxi app has a larger marketcap compare to bitcoin
the answer is quite obvious uber is part of a normal ,average and even to some important people's lives,
almost everyday people use this app as means of transportation
while bitcoin on the contrary has a small percentage of community using it as per date
This is 2014 chart But we are all live in 2018.
1. Uber market cap is 51 billion .
2. Bitcoin market cap is 152 billion.
So everything is depends on demand currently cryptocurrency is rule the entire market so no one compare to the Bitcoin market cap.