In my mind, that means we need to see deployment of Gen 4 fission reactors (https://en.wikipedia.org/wiki/Generation_IV_reactor) commercially, to bridge the gaps between a decline in coal-fired plants and the potential of renewables.
There probably has to be a machine before DEMO to solidify the engineering and materials.
Also, after ITER, there will not be enough tritium to do another large machine (the tritium comes from heavy water reactors, but those have lost in the market and will be shutting down in the next couple of decades.) So a machine to just make tritium may be needed.
In my mind, that means we need to see deployment of Gen 4 fission reactors (https://en.wikipedia.org/wiki/Generation_IV_reactor) commercially, to bridge the gaps between a decline in coal-fired plants and the potential of renewables.