From my limited understanding, it is just iterative improvements in fusion that are required. You shoot a laser at something compressed in a strong magnetic fie

From my limited understanding, it is just iterative improvements in fusion that are required. You shoot a laser at something compressed in a strong magnetic field, and use the dissipating heat from fusion to boil water to spin turbines to power the laser and magnet. This whole process already works, but doesn't net energy gains. Improvements in efficiency of the laser, magnets, or power gen could make it tip into net energy gains. It's still an engineering problem from then on, as you need to compete on $/Kwh.