Why is VK_BUFFER_USAGE_STORAGE_BUFFER_BIT required in the buffer_device_address example?

The VK_KHR_buffer_device_address example says that VK_BUFFER_USAGE_STORAGE_BUFFER_BIT is required:

https://github.com/KhronosGroup/Vulkan-Samples/blob/43c23e56dab295e2e83903c69053927afbddac45/samples/extensions/buffer_device_address/buffer_device_address.cpp#L239-L242

But as far as I can tell, the vulkan specification only requires this bit for descriptors and ray tracing. I don't believe that either of those apply to the example.