If that "productive thing" isn't productive enough to yield better than an asset that just sits there in a cold storage, I would argue it wasn't all that productive and/or efficient to begin with.
People will always spend for things they need, they'll also spend it for things they want, but the current fiat system is forcing to spend it just for the sake of spending it forcing over/pointless consumerism on everyone.
People will always spend for things they need, they'll also spend it for things they want, but the current fiat system is forcing to spend it just for the sake of spending it forcing over/pointless consumerism on everyone.