Why is it important to use spur plates with ladders?

Using spur plates with ladders is essential for providing stability on soft or uneven surfaces. These plates help distribute the weight of the ladder over a larger area, reducing the risk of sinking or tipping. This is particularly important when working on ground that is not firm, as it ensures that the ladder remains secure and balanced while in use. By enhancing stability, spur plates significantly decrease the likelihood of accidents and falls, which are critical concerns in ladder safety. The other options do not address the primary functional purpose of spur plates, which is to ensure safety and stability during ladder usage.