Against it, because, firstly, in terms of trust, nothing will really change. Yes, there will be cases where a moderator is unanimously chosen, but I remember that in the forum of one online game, such a thing led to the fact that the elections were difficult - each guild voted for its own person, and as a result, the chosen moderator favored his own. It is clear that since he was chosen, there are more people in his guild, but... Here, perhaps not with guilds, but the same thing is possible. On the other hand, elections by the moderators themselves are not always objective, I agree. But, in the end, you can always question the actions of the moderator.
And secondly, what threshold should be set in the case of a public vote? How much time will it take, how many people need to vote. It is easier to gather a couple of dozen moderators.