If there were two tokens, one of which was stakeable and the other not, traded separately but convertible, then sure. But that's not reality. ETH's value is in

If there were two tokens, one of which was stakeable and the other not, traded separately but convertible, then sure. But that's not reality. ETH's value is in part defined by its ability to bear interest. Whether you personally stake or not has no bearing on whether your ETH is a security.