Every extra million a billionaire squirrels away means less desperately needed policemen, firemen and teachers that can be afforded, let along safe bridges and roads.
But you’re not going to see average humans up and arms over this because of the way nature has programed us all. The human base foundation ego has one primary mandate and that is to survive and prosper to that end at all costs. This most primitive impulse has no governor as to how much is enough. That sort of logic lives in the intellect, an intellect that escapes a huge portion of the population.