It's not really silly at all. It is there for two reasons.
(1) The law requries it to be stated in contracts [at least partially because of (2) below].
(2) Case law develops and can mean that something in a contract was previously enforceable but due to a test case or other development, it is no longer enforceable. Rather than companies having to watch every test case go through the courts and have lawyers rewrite contracts every few weeks just in case something needs updated, the catch-all allows for a more reasonable update cycle with rewrites only happening when there is a significant change to legislation or a number of cases has resulting in significant numbers of terms being invalidated. Pending the rewrite, the term makes it clear any updates to legal interpretation are honored.
In the EU there is also a choice of venue available to consumers so often the 'rules of country X' are not so readily enforceable for companies when they deal with consumers across EU borders. But that's a whole other complicated area.
(1) The law requries it to be stated in contracts [at least partially because of (2) below].
(2) Case law develops and can mean that something in a contract was previously enforceable but due to a test case or other development, it is no longer enforceable. Rather than companies having to watch every test case go through the courts and have lawyers rewrite contracts every few weeks just in case something needs updated, the catch-all allows for a more reasonable update cycle with rewrites only happening when there is a significant change to legislation or a number of cases has resulting in significant numbers of terms being invalidated. Pending the rewrite, the term makes it clear any updates to legal interpretation are honored.
In the EU there is also a choice of venue available to consumers so often the 'rules of country X' are not so readily enforceable for companies when they deal with consumers across EU borders. But that's a whole other complicated area.