Gold is rare, compared to just about every other element, in accessible areas of earth. All the gold ever discovered on Earth would fit inside a 23 meter (75 foot) cube. This is about 244 thousand tons, in all of human history.
Compare this to iron, where just the United States produces 46 Million tons in 2022 alone.
There is plenty of gold deep within the Earth - it is very dense, so it sank towards the core when Earth was recently formed - but on the surface and the proximal crust, it is not found in abundance.