I found this useful

The Problem with Ikigai https://www.youtube.com/watch?v=TeX6kNbaF0w

The TLDR I got from is that first - that the diagram itself was made up by someone trying to write a business blog/book.

The second is that the goal is not to find one singular activity to cover the intersection of the Ikigai Venn diagram. Instead it can be better to have multiple different activities which ensure the union of the Ikigai Venn diagram is covered so you aren't myopically focused on one area of it.