Ironically the happiest and healthiest retires do more than the bare minimum. Maybe it isn’t work but they’re staying productive (or busy?) in many ways. Not doing things is really destructive to the human psyche.
Unproductive in economic terms. They not contribute significantly to the tax base compared to what they used to.
Painting in broad strokes, of course. I'm sure somebody somewhere is working harder than ever, but it is not the norm. Long walks in the park and meeting with friends doesn't contribute to the tax base.