Forgive me, but I do not know whether my question was received, so I will ask again: Maimonides claims that one may not go out to an optional war unless they consult the Sanhedrin. Is that not true for our times as well?

Why not?

But the Rabbi himself argues that if the rabbi being asked is not knowledgeable in the field of the question being asked, it is not right to consult him—certainly not when it is a question of whether to go to war, just as the Rabbi gave the example from the coronavirus period.

Do you want me to repeat myself again? As I wrote, it is worthwhile to consult with any wise person, even in areas that are not his expertise. It is worth investing a minute to think before asking a question.