What is a common consequence of not properly caring for leather?

Not properly caring for leather leads to a loss of resilience, which is critical for the durability and longevity of the material. Leather is a natural product that requires regular maintenance to keep its strength and flexibility. When leather is neglected, it can dry out and develop cracks, which significantly reduces its ability to withstand stress and wear. Additionally, the loss of oils due to improper care can lead to stiffness, making the leather less comfortable to use and more prone to damage.

In contrast, the other options do not accurately reflect the consequences of inadequate leather care. For instance, leather does not become more flexible when neglected; in fact, it becomes stiffer and less pliable. It also does not naturally gain oils without appropriate conditioning; instead, it can lose these essential nutrients. Furthermore, while leather can darken over time due to factors like exposure to sunlight or certain conditions, this is not a direct result of neglecting to care for it. Regular, appropriate maintenance is key to preserving leather's quality and performance.