First of all, I would like to show you similarities between Bitcoin and gold.
The value of both are driven by both scarcity and demand.
The both are decentralized, and the both have limited supplies, the list goes on...
The supply of gold in the global market might be controlled but I still doubt if the supply is limited. There are still many untapped gold mines, and some illegal gold markets still exist. But Bitcoin supply supply is limited.
Bitcoin or Gold which is worth investing in?
Both of them are good investments, but gold has lasted for a longer period. Bitcoin is technologically driven and has the advantage of promoting privacy. A good investor would diversify his portfolio, and both of them are good areas to invest in.