Bitcoin is very young compared to gold. Although it has proven itself as an investment tool, it has not been able to reach many people who like to invest traditionally. As time goes by and generations interested in technology grow up, interest in Bitcoin will increase further.
This is a process and there is no need to rush in this process. There are many investment instruments and people choose these investment instruments and make their investments. The advantage of Bitcoin is that it reaches more people every day.
There are two advantages of Bitcoin that I can think of which I think are the reasons why many people might prefer Bitcoin as an investment option over Gold. The first advantage is affordability, by affordability I mean that a person can start making investments in Bitcoin from as low as $10 which is extremely low and it means that any person having that much money can become a Bitcoin investor. The other advantage is that it is more volatile than Gold which means that the potential to generate profits is higher than Gold in the shorter term.
Gold is one of the best investment assets in the world, there is no doubt about that, and it has been around for centuries which is the reason why many people trust it more than Bitcoin because it has a physical existence unlike Bitcoin which is only available digitally.