That’s not the only way people use it, but even in that case you are DCA-ing a fixed fiat-denominated amount, rather than a fixed amount of sats per DCA. You can’t ignore the fiat price of bitcoin in real world contexts because the fiat price is just another exchange rate related to purchasing power. It’s a silly catchphrase that people who want to be cheap toss around. “Oh you want to charge a fair market rate for your services instead? 1 sat = 1 sat bro. Give me a discount.”