That's because everyone else has access to the same tools. If you don't become more productive then you will be replaced with someone who will.
They only way it'd help you is if you controlled access to AI and it was a competitive advantage for you over a fellow developer. A rising tide lifts all boats... but you are only paid for how much taller you are than the other boats.
It's important to understand that AI is capital, and it's to the owner of the capital go the spoils. Your capital is in your skills, but they are a commodity and thus you have limited leverage.
Who benefits from AI is smaller businesses who could not afford custom application development at previous development costs. It's like faster laptops and better IDEs didn't boost developer salaries.