The versatility of an iPhone 15 case depends largely on whether its size and design are compatible with a particular model of iPhone. Within the iPhone 15 lineup, the size and design of different models (e.g., iPhone 15, iPhone 15 Plus, iPhone 15 Pro, and iPhone 15 Pro Max) may vary, so their cases are generally not universal.

　　Specifically:

　　Size differences: iPhone 15 and iPhone 15 Plus are relatively close in size, but may not be universal due to subtle differences. The iPhone 15 Pro and iPhone 15 Pro Max, on the other hand, have cases that are even less universal than the other models due to their increased screen size and different body designs.

　　Design differences: In addition to size, different models of the iPhone 15 series may also have differences in body design, camera layout, and other aspects. These differences can affect the compatibility and versatility of the cases.

　　MagSafe compatibility: For iPhone 15 series phones that support the MagSafe feature, their cases need to have the appropriate MagSafe compatibility to work properly. This means that if you intend to use MagSafe accessories (e.g. magnetic chargers, magnetic mounts, etc.), then you need to choose a case with MagSafe compatibility.

　　To summarize, to ensure compatibility and versatility of the case, it is recommended to choose a case that matches your iPhone 15 model. When purchasing, you can check the product description and specification information of the case to make sure it is compatible with your iPhone 15 model. Meanwhile, you can also refer to user reviews and feedbacks to choose phone case brands and products with good quality and compatibility.

　　Translated with DeepL.com (free version)