... Then we get into the possibility of power from nuclear fusion. I know it's one of those things that is always 'a few years away' - but cheap energy (free? unlimited?) is getting closer all the time.
I think this kind of highlights the fact that technology is racing ahead of us, and it won't be long before it goes way beyond the ability of mere humans to understand, and it is computers themselves doing the thinking and theorising. The most promising form of defence against quantum attacks currently under development seems to be NTRU, which relies on some quite esoteric lattice-based maths which is frankly already beyond my ability to comprehend. In a few years' time I can imagine that it is computers themselves coming up with these models, and humans struggling to keep up. It's an infinite arms race into the distance really. So long as there is one side attacking and another side defending, it's difficult to see where it will stop - unless there is some fundamental facet of quantum mechanics that provides a final barrier to one or both sides.
Nuclear fusion is something which is getting closer by the day in fact in Boston they recently got a 50 million dollar dollar investment for their nuclear reactor. They believe they've sussed out the laws and its only a matter of building the plant. The theory has always been there and theoretically its safer than other traditional nuclear power management systems however we must consider chernobyl was considered safe no matter what due to the fail safe system they had in place. A great program was recently released which showed how out of depth they really were and this start up in Boston that claims to have all the answers and the only missing puzzle piece is actually building it has no track record. Therefore despite the claims of nuclear fusion being the future we have to consider how far and how many hurdles we are yet to hit.
Despite the lack of experience lets assume that all goes well and nuclear fusion becomes a thing. How accessible will this be to the public? Do we really believe energy companies will be providing cheap energy via nuclear fusion or will this still be reserved for the elite very much like quantum computers?
We also have to consider the moral obligations and the public viewpoint of nuclear power. At the moment there are multiple different organizations which are trying to combat the development of nuclear power plans and which could put a halt to nuclear fusion. I'm actually for the development of nuclear energy and providing a more efficient energy system but I can understand the concerns about accidents and management of waste and how it can literally destroy the environment it is in.
In conclusion even if nuclear fusion becomes a thing in the next few years and quantum computers could be cooled at the temperature required at a decent price I highly doubt that other than the wealthy elite the power of nuclear energy will not be easily accessible.