No, it's not. That's like saying it's the CEO's job to write every design document in a company.
It not only doesn't make sense -- it's not even possible from a perspective of information throughput.
It sounds like you're saying that Congress should approve drugs rather than the FDA. Absolutely not. Congress should write the regulations that govern how the FDA operates, and then the FDA should operate.
And let's remember -- if Congress doesn't like what a regulatory agency is doing, it can pass legislation to change that. If it doesn't, we can assume it approves. Therefore the courts have no business stepping in -- except obviously when there is genuine conflict between laws or with the constitution. But that's not what you're talking about.