I make bitcoin a long-term investment because bitcoin has a limited amount while gold has an unlimited amount, and if many countries are busy making bitcoin their currency back up then I am sure the price of gold will crumble to smithereens.
About 210 tonnes of gold have been mined in human history. So the amount is limited, which is why it keeps its value.
based on the article below, the number has not touched it;
The best estimates currently available suggest that around 208,874 tonnes of gold has been mined throughout history, of which around two-thirds has been mined since 1950.
source--but there is something a little strange in my opinion, in this article it is written that the number of unmined gold reserves is only around 57 thousand tons but it is still based on a survey in 3 countries (China - Australia - South Africa) but why are other countries such as rusia not counted, because currently Russia and the US are still actively producing gold reserves (and many are not yet mined),
About 244,000 metric tons of gold has been discovered to date (187,000 metric tons historically produced plus current underground reserves of 57,000 metric tons). Most of that gold has come from just three countries: China, Australia, and South Africa. The United States ranked fourth in gold production in 2016.
source--I forget where the topic I have read is, but someone has reported that gold reserves have been found on Mars, which means that the amount of gold cannot be estimated.