It’s because nobody needs gold right now. There’s no gold sinks. Gold is uaully wanted at the start of expansions for gear/professions etc
But later on? You don’t need it. All I spend gold on is repairs, and raiding stuff. And I make the gold I need by just raiding and stuff. I don’t need a lot. And if people don’t need gold, they aren’t putting out $20 for 200k