If I have two or more kinds of things for a similar purpose (pencil and pen, powder and liquid cleansers, more than one pair of shoes), and they are both (or all) exhaustible, there must be some reason for having more than one. Perhaps it’s the insurance you get from redundancy, or perhaps it’s because the different traits make them optimal for different purposes. A light, delicate pair of strappy high-heeled sandals is not going to wear longer than a pair of thick rubber-soled boots, but I would choose them over the boots for summer social events.
For as long as I had the choice, then, I would want to keep both and use each one as intended. For instance, I would prefer to use paper towels for something that is going to be nasty to wash out of a cloth rag, even if the rag would be reusable, unless paper towels would not stand up to the task.
In an apocalyptic scenario, I would definitely want the boots, the rag, and the pencil.