Remember when incandescent light bulbs were the norm? They worked by sending full line voltage through a tiny tungsten wire that would get so hot that it glows, making some light, but 95% of the energy that gets consumed is frittered away as heat? The high-power lasers needed to make fusion happen are a lot like that.
I believe all this article is saying is that 15% more energy than what came out of the lasers as useful laser light was liberated in the reaction.This completely ignores the energy it took to power those massively inefficient lasers.
I think it also ignores the fact that the 15% more energy liberated wasn’t actually, like, harnessed by a generator. I believe (and I may be wrong) this was testing only the reaction itself. Actually hooking that up to a turbine and using it to create energy that is cost competitive with contemporary sources is still a completely unsolved problem.