How did Australian farmers become dependent on toxic weedkillers?

Australian farmers used to grow crops like wheat and canola on big fields. One day, they found a new tool, toxic weedkillers, which helped them get rid of weeds easily.

At first, the toxic weedkillers worked super well. It was like having a robot that came in every few weeks to clean up the garden, no need for hard work or waiting long for results.

But here's the catch: the weeds got used to the weedkiller, just like how your little brother might stop listening when you say "clean up your room" too often. Soon, the toxic weedkillers needed to be used more and more, sometimes even twice a year. And that’s when farmers became dependent on them, because stopping would mean going back to the old, harder way of farming.