I think Congress does have power, it's just chosen not to wield it to control this presidency.
Congress does not have an army they can send out to enforce any law they pass, so turns out the president can simply just ignore it all without consequences. What are they going to do?
Exactly, that's the bug. Two of the three branches of government can only write sternly worded opinions on paper. Only one has the brute force to impose their will. So there really is only one branch of government in the US.