Your argument defeats itself because there obviously is a demand for Bitcoin that is large enough to prompt entire countries to adopt it as legal tender. As such it
obviously has value. What traders disagree about is
how high that value should be compared to other things.
Notice for instance how fewer and fewer people are interested in selling Bitcoin the lower it goes. But I bet you'd love to get people to believe it's worthless so you can get it at a discount. Again, this proves that Bitcoin indeed has value.
As for artificial scarcity; well, artificial or not, at least Bitcoin has scarcity. Obviously artificial trinkets in the form of worthless metal coins, paper notes, or numbers in a bank's database, does not have any meaningful scarcity compared to Bitcoin.
Btw, whatever scarcity there is for fiat is also just as artificial, except its rulers and influencers can make as much of it as they like depending on their mood that day. Not so with Bitcoin. Artificial or not, its supply is hard capped at 21 million coins.