I was wondering... When nuclear fusion becomes a thing in "the next 30 years", i.e., almost infinite and free energy production, what do you think will happen to proof of work? Will make the bitcoin consensus stronger or weaker?
Nuclear power is not a trend for the future. Many nations and foundations are trying to reduce operations of current nuclear power facilities as well as trying to shut down old facilities and won't intend to approve licenses for new facilities.
After the Fukushima Daiichi more than one decade ago, the world has been changing core approach to nuclear power.
If nuclear fusion is going to be centralized, as it seems for now (look at the ITER), then I think it can be a problem. Nation-state attacks could be feasible.
Nations, governments can set up mining farms and mine Bitcoin. Bitcoin is opened for everyone, every institutes, nations so they are free to do this. If they do this, they will do it very secretly. They won't announce anything because they don't want to admit their systematic failures.