Yes, of course that is true. When I said that QC is "just an engineering problem" I did not mean to imply that it was straightforward. It's not. It's a Really Really Hard engineering problem with a lot of unknowns. It might turn out to be like fusion, perpetually 10-20 years away. Or it might turn out to be like the blue LED, seemingly impossible until someone figured out how to do it. I think you'd be foolish to bet your life savings on it either way.