Bitcoin would give quick returns than Golden? Yes. Then why didn't they invested earlier?
Well, without any doubt.

Bitcoin has proven itself as more profitable for investors throughout those years than gold and there's no doubt if someone invests in Bitcoin then that person will get quicker and higher profits then the ones who invest in gold. The ones who haven't invested in it earlier were skeptical and now they're investing due to FOMO.
I will not deny that gold investment is not a profitable investment but gold investment is not profitable to bitcoin. We can see how Bitcoin has been rising for the past few months but the price of gold has never risen like this so every Bitcoin investor is now in a very profitable position. I have gold investments and bitcoin investments but if I had invested in bitcoins instead of gold I could have bought twice as much gold today with that bitcoin profit. I would definitely vote for bitcoin investment if there was a voting system.