Demand for gold as a material in industry is too overblown, probably only take 7% of the total demand. The demand for investment and jewelry surpass it by significant margin and even jewelry is just another investment.
Though i will agree that nothing will change if bitcoin become global reserve, we just gonna have 2 asset that can be used for global reserve and thats it.
More specifically, gold used in industry accounts for more than 11% and the electronics industry accounts for nearly 7% compared to the medical and culinary industries which only account for 1-2%. But as the need for technology increases, the need for gold in industry will also increase because so far there is no material that can replace gold.
Jewelry is the industry that accounts for the largest share of gold reserves at 55% and this may also be the form of investment that bitcoin cannot replace.
Most likely gonna take some of gold demand but thats about it. Most people will definitely diversify between the two though.
Gold demand has declined but not significantly, and specifically, inflows into gold ETFs have been weaker than those into bitcoin ETFs in recent months. But gold ETFs only account for a small percentage of the total gold supply, and that is why I believe nothing serious will happen to gold because of bitcoin.