3. Bitcoin is practically referred to as a commodity, which shows similar characteristics to gold. The process of acquiring either of them will definitely lead to a reduction in supply; i.e., the more we mine, the more they are reduced.
At least for now bitcoin and gold supply have different characteristics. Since bitcoin has been created, the supply is meant to be 21 million. Which means after the whole 21 million BTC has been mined, there will no more be new BTC that would be introduced into the calculation. But check this about gold:
Major gold deposits discovered in UgandaOn June 7 2022, approximately 31 million metric tonnes of gold was declared by their president to have been discovered in the country. There are many of this kind of news that a country will discover gold or more gold deposit. Which means the supply are increasing.
These are the gold on the land surface. There are still gold in the earth crust and beneath the ocean but which modern day technology can not mine. Also there are gold deposit outside the earth on other planets. Example is Psyche 16. We do not know how advance the world would be in some centuries to this time and we can not just conclude that gold deposit is limited.