Goverments control gold price and they wouldn't let to speculation. BTC is not controlled by a group and it can't be more stable than gold. Compared to gold, there are also so many differences in supply and demand.
That's correct people will rather prefer cryptocurrency than gold. I have mentioned on many occasions that popularity makes a product or stuff more and more popular. Gold will be very stable as it goes up and down in a very rare instance. Crypto will give you a good return with good profit.