She's asked "Must there be a Superman?" under the context of Superman's role in the world. Her response of "there is" speaks to how there isn't an answer to the question, but there's no going back to a time before Superman.
And as much as people mention Superman not speaking during the court scene, it's to reinforce how he feels responsible, voiceless, and weak despite all his amazing powers. By that point we've seen several times how he's been questioned for doing the "right thing," when in the modern world, it's not so black and white. Both as Superman and Clark Kent, blocked by Perry for wanting to write about underprivileged folk getting affected by the Batman's actions.
I don't know if people wanted him to be an egomaniac, walk into that court, interrupt the senator and start yelling about how he's a nice guy and everyone else is wrong but him. Senator didn't even finish her intro by the time it popped off.
She didn't state her case for
why we need him. Given this was a big problem with how the critics were angry over his version of Superman, the least he could do was make a defence and neither of the scenes bothered trying. Snyder could have made a logical argument here but as usual chose not to embellish, if he ever actually thought that deeply about the character.
Emoting is useful in movies, being mute is not (unless they're Jodie Foster) and I don't know why but Snyder was annoyingly obsessed with Superman not talking to anyone about anything. The best we got was a scene with Lois, which we needed more of. Communication is key in a media like movies, and his Superman wasn't interested in explaining himself to anybody. This approach, while making him look like a deity, made him look arrogant, makes Batman's argument stronger as he appears like an angry god who will snap at any moment and gives barely any reassurance not believe the worst in his intentions due to his actions. We're supposed to take too much on trust unearned that he is worthy of our respect while he flies dictators through walls like it aint no thing.
That Perry scene made no sense, and if you're right it was wasted as the analogy was too subtle to connect to his life as Superman. I knew and understood more about his life as Clark then I ever did as Superman because as Superman he's an opaque brick wall who is solely interested in killing first, ask questions later. He's a journalist who would have his jurisdiction on a subject, not a sports writer.How his Clark and Superman lives were written there was very few overlapping mannerisms so it felt like I was watching two seperate characters, unlike in MOS. Clark I could understand and feel empathy for.
The movie did a horrible job if you're right about them trying to make the world a grey area, when both Batman and Superman viewed everything around them in black and white with extreme prejudice. Aside from Wonder Woman, who was written with the implied subtlety to understand nuance like that but aside from fighting Doomsday and hiding from the world was never allowed into the conflict between the two.
That wouldn't be my first choice to how I'd want Superman to address the court, but the fact that what you wrote didn't seem out of place for this Superman speaks volumes for how out of touch Snyder was with his character. He should have been able to defend himself in court like everyone else and get them, and the audience, on his side. Except Synder wasn't interested in the movie defending his choices, he wanted to double down and appeal to his own authority that he was right.