How has the UKSC been Unsuccessful?

-UKSC doesn't have that much more Power than the Body it Replaced. Only can Interpret Law done by Parliament, while European Courts can Strike down Laws that are 'Unconstitutional' UKSC only gets power that Parliament gives, and it can be taken away. The Conservatives in 2019 Manifesto wanted to review the UKSC Powers, perhaps affecting how it can hold Government to account. -On the Left, the Court has a 'Conservative Bias' due to the Narrow and Social Background. On the Right, they say the Court has entered the Political Arena. 2017 saw the Miller Case, denying the Government to trigger Article 50 without Parliament's Approval