The evidence and reasoning by Congress was all "non-justiciable" by the courts.

Congress looked at some evidence and made a decision. That is their purview and our checks-and-balances do not allow the courts to second-guess Congress like that. They can look at the "how" of the law, but not the "why".

Specifically the court looked at "what is congress' goal and is there any other way to achieve that goal that doesn't stop as much speech" and there isn't, but they can't question the validity of Congress' goals.

So there's no point in Bytedance arguing any of it, at least not in court.