Why would they think/assume that URLs have infinite durability? If you buy a floppy disk with some data, it's very likely that you can still get the data that it holds if you manage to get a Floppy Disk Drive. But you cannot expect any change in the evolving conditions that allow you to get a floppy disk driver.
It's very likely that there would be something that replaces URLs in the future.
Amazon promise seems to be that they will always keep your data integrity and keep it accessible. The way I see is that they will be moving my data to newer or better storage types and will keep my data unchanged regardless of any technology change.
To keep with the analogy, Amazon's promise here is that they will always keep the data that you originally stored in your floppy disk, but they cannot promise to give it back to you in a floppy disk. Next year they might give it back to you in a CD and the year after in a cartridge.
The data has been always there, intact. They are just giving it to you in a different medium.
It's very likely that there would be something that replaces URLs in the future.
Amazon promise seems to be that they will always keep your data integrity and keep it accessible. The way I see is that they will be moving my data to newer or better storage types and will keep my data unchanged regardless of any technology change.
To keep with the analogy, Amazon's promise here is that they will always keep the data that you originally stored in your floppy disk, but they cannot promise to give it back to you in a floppy disk. Next year they might give it back to you in a CD and the year after in a cartridge.
The data has been always there, intact. They are just giving it to you in a different medium.