Marie Kondo's spark joy meme was a great inspiration for many Japanese. In particular, the fact that she was able to do a popular Netflix series without substantially speaking English, I think, gave the Japanese an intriguing thought, an epiphany for many young people, who are always told that their English abilities are not adequate for the global era.
The spark joy approach itself is very interesting too, and tells something deep about the Japanese psyche. Ever since the great Pillow Book essay by Sei Shonagon (completed in 1002), joy to the heart has been an important guiding principle of Japanese life. The great achievement of Marie Kondo was to bring the venerable approach to the world arena.
Marie Kondo applied spark joy to decluttering in the household. In more general terms, people can apply the spark joy principle to life's wider choices. Does one particular activity spark joy in yourself? The answer to this question would reveal what actions would activate your brain's reward system, telling you how you could make yourself grow both professionally and personally. Marie Kondo's achievements are great. But most probably, spark joy is wider than decluttering.