Unlimited very low-cost energy, that doesn’t harm the planet or it’s inhabitants in any way.
I think that this advancement might change the world as we know it. I feel that so much of the conflict in the world revolves around energy production and consumption. I believe that there would be a massive re-alignment of the earth’s resources if we could all have equal access to energy. Less crime if we could afford what we need, because the lower energy costs don’t drive the expense beyond the reach of anyone. More usage of technology because the cost of producing and operating said devices is less prohibitive.
We’ve probably all been exposed to ideas about possible futures where people must contribute fewer hours to earning a living and supporting the economy, and have much more time to explore and create art, pursue advancement for it’s own sake, education just to satisfy our intellectual curiosity or serving others out of the poster’s mentioned universal compassion, which by the way, I appreciate. Compassion might be more universal when resources are more available to every human being.
I’m not sure about this, as there could be other mitigating factors that I have not considered, but this might be my best possible world.