It depends on how we talk about leaders. If we mean people with or without formal positions of power who connect others in sharing talents and realizing common dreams, we need as much leadership as possible. If we mean people with formal positions that exercise instead of share power and empower, we need very few to grow thriving communities.
Communities thrive when people share responsibility and resources. They struggle and implode to the degree that leaders divide communities into responsibility and resource haves and have-nots.