With the internet archive, the purpose seems to be for public archiving. One could imagine a use-case where you want non-public archives, and are therefore not subject to any take-down requests, especially if they are considered court evidence for example.
By paying directly for your links to be archived, it directly helps fund the service and therefore keep it going. You would want to see some guarantees in the contract about pricing if you were to long-term rely on the service.
With the internet archive, the purpose seems to be for public archiving. One could imagine a use-case where you want non-public archives, and are therefore not subject to any take-down requests, especially if they are considered court evidence for example.
By paying directly for your links to be archived, it directly helps fund the service and therefore keep it going. You would want to see some guarantees in the contract about pricing if you were to long-term rely on the service.