Wages aren’t set arbitrarily, they are set by market rates.
They could pay $30, but they’d rather have those people do more productive time than waste their skills labeling stuff. Paying skilled people to do unskilled work is a recipe for sadness and depression.
Why not suggest they pay $200/hour. I mean OpenAI has the money, right? $15 is high pay to sit at a console and label stuff. People literally make the same for cooking burgers and most retail jobs pay less. And these jobs don’t require a lot of training or skill, that’s why they pay so low.