I like the way you organize your three types of purpose. I’ve always seen it as binary; short term purpose and long term purpose. I see short term purpose through the Maslowian needs that you allude to. These are real, and are the reason why in most studies about “happiness” or “satisfaction” there is some type of income threshold that must be crossed. It’s hard to search for a higher purpose when you are hungry or scared or threatened.
Teachers, philosophers, history, and apparently Nate Sr., however, have all suggested that once that threshold is crossed, the path to long term purpose lies not in achieving more, but in serving something larger than oneself. I wonder though if the root of that is our mortality. I wonder if serving something larger than oneself allows us to transcend our mortality and affix our legacy to something that will invariable carry on long after we have passed.
Kind of morbid, certainly heavy, but just a thought.