We can already massively increase generation to meet the needs of those industries whenever we want. They’re impractical due to the cost of meeting their energy requirements, not because it’s impossible.
Unless fusion power plants are going to be free to build or last forever, they have the same practical limit as every other type of generation - they have to be paid for. It isn’t clear that fusion would be a huge step forward in cost per megawatt-hour.
For games that aren’t fast moving, you don’t need 240fps in the first place.
I played an MMO at 40 FPS for years. With a freesync screen that matches the frame rate instead of stuttering or tearing, it still feels fine.