That chart was so confusing it made me angry
I think it's that the y axis is doing too many things? It's "losing ability to see spirits as you age" AND "how many people can see each stage of spirit?" Also it the ages progress up to down instead of down to up. And the arrow saying "becomes harder and harder to notice" is pointing at "blank" the easiest spirit to notice.
Maybe something like
👶 | 😐🙂😠😢🫨 <- can see all stages
10 | --------------
🧒 | 😐🙂😠😢
30 | -----------
🧑 | 😐🙂😠
50 | --------
🧓 |😐🙂
70 | -----
🧙♂️ | 😐 <- can only see blank