Is there a point at which too much investing and less spending has a negative effect on the economy? If too many people stop spending and start investing either in traditional assets or crypto currencies there will be less money to spend on products produced by the projects that receive the investments.
I am hoping the crypto currency technology will evolve into something that will actually simplify the existing financial system and will benefit the economy in the long run. I doubt that it is going to be Bitcoin just simply because it was never designed for scalability, and Lightning network is unlikely to be widely adopted. I would like to see a successful project in 2018 that uses a crypto currency, a project that would have been difficult to realize with traditional currencies. As of now, as you repeated many times, all it is just a pure speculation.