Gold has been mined out steadily year over year. We know gold is scarce and we also know there is more in the ground.
No one is sure about the gold supply. But every bitcoiners know the supply of BTC.
Yes and no but it is the reason for the gold crunch this month.
You see gold, like every resource follows the Hubbert Curve. Peak gold was projected to be some time around 2020. Now what happened was that gold futures piled up to such an extent that it became questionable if it really is this early, not later. So speculative interest coming form the assumption of declining supply rates after that date went away and the price plummeted. Of course gold-bugs will tell you that was because market manipulation or "fake" gold futures for gold which isn't really there, but we should know better
But this does not mean that peak gold won't happen within the next decades so the gold price will not deteriorate completely.
That argument would only hold water if gold was a commodity that gets used up, like oil. However gold is not really a commodity, it is primarily really money, which is why central banks hold it. Almost all the gold ever dug up is still available to go to market, therefore there is a huge potential supply of it that far outweighs any new gold coming to market from mines. The laws of supply and demand should ensure that when more demand is there then the price goes up accordingly.
Where it all goes wrong is in fact what gold bugs will correctly tell you, that in the futures market the big commercials can sell as much gold as they want without having to actually possess the metal they are selling. Despite the fact they are not really selling physical metal, this actually is permitted and the amounts are vast. This mechanism enables them to manipulate the spot price almost to any degree they choose. In other words the spot price of gold is not really much to do with a physical market. And in fact because gold is not really a commodity it has no business being in a futures market in the first place.