That's like saying if the cost in USD of chocolate from Switzerland changes with USDCHF then you're not actually paying in USD. All international transactions

That's like saying if the cost in USD of chocolate from Switzerland changes with USDCHF then you're not actually paying in USD. All international transactions are affected by exchange rate, it's just a question of to what degree the importer is willing to eat the cost of minor fluctuations. This is more likely to occur with high-margin consumer items (e.g., Nintendo games tend to stay priced at round numbers) than with low-margin items. Gold and BTC both approximate pure financial instruments and are notionally almost zero margin. Thus we would expect their prices to be quoted very precisely.