Because while the post-war Confederation was anaemic, leading to the Founders adopting a new constitution that would give the federal government more power, it was only enough power as was deemed necessary at the time. For example, Congress must name the powers upon which it is acting. It may require nosediving down a rabbit hole of citations to other laws, but at the end of that trail is a reference to an enumerated power within the Constitution.
Congress may be dysfunctional, but that doesn’t magically enumerate more powers to the Supreme Court; the Supreme Court must act within its remit. And as I mentioned in another thread, the federal judiciary is the least defined branch of the three, which given the enumerated nature of the Constitution should mean the federal judiciary should be the most restrained. Except that the Supreme Court has arguably become the most powerful branch due to their self-proclaimed stewardship of the Constitution that neither of the other branches can check or balance.
