Why are people using dollars as a metric for measuring purchasing power parity?

In Argentina, where I live, 1 USD = 600 ARS, but the average monthly salary is 2,000 USD and the poverty line is 93 USD. This means that the average person can buy more than 4 times the minimum wage with their salary when they can only afford half of it with 1 USD. <br><br>Why are people using PPP as a metric for measuring poverty when it's totally inaccurate?