I don't know why you think we can possibly come up with a competitor to something that, left alone for 20 years, builds itself into an incredibly strong & versa

I don't know why you think we can possibly come up with a competitor to something that, left alone for 20 years, builds itself into an incredibly strong & versatile building material, while sequestering carbon, using what amounts to crazy self-replicating nanotechnology from several hundred years in the future.