let's use early hunter gathering societies as an example
- Si would have been useful for everyone. harvesting grain and farming in general require an obscenely uncomfortable amount of routine for non-SJs. more importantly however, if you cannot remember and pass on the lessons of the past, no permenant progress can be made and each generation has to start over from scratch. this is why today you see SJs making up about 45-50% of the population
- Fe would be the most economically advantageous for women. due to their anatomy, lower level of physical strength and need to remain safe to produce and take care of offspring, they have in the past been more suited to domestic pursuits. taking care of the work around the huts (cooking, making pottery, taking care of the children, taking care of the hunters' injuries). also, Fe would create a common culture and keep the tribe together collectively. this is why i think about 50% of women are FJs
- for men, Te and Se would be extremely advantageous for hunting. Te for drawing up hunting plans and Se for it's physical prowess. this is why we see a lot of STJ men and SP men
- more than a baseline level of intuition would probably not have been very useful during those times, even if today being N is probably slightly advantageous
- same goes for Ti and Fi. neither of these would have been particularly useful beyond a baseline point. however, Fi, Te and Si combined would have been good for making the first legal structures and Ti is a good skill to have if one is a craftsman, as many were in the earlier times
- the value of Fi by itself is not really linked to real world/tangible things as it deals with ideal, fantasy and aesthetics. this is why I think Fi has a reputation for being supernatural and often connected with magic or mythical creatures. the first myths and fairytales of old were probably devised by NFPs and would be useful in teaching the younger generations wisdom and life lessons.
anyway, just a theory