If people were 100% rational, would the world be better?

[Neo-Scholastic]

Emotions are directed towards goals.  Most people can agree on the top of the pyramid, staying alive, but from there the goals diversify like lines in a branching story.  At the bottom, where goals are implemented, the variety of aims and purposes representing the top-level goal are so varied, that all you can say is that whatever a healthy brain wants, that's appropriate to the goal.  If rational means simply having a reason, then all these bottom-level wants become rational as they are all reasons justified by the legitimate top-level goal.  In that case, rational becomes so dependent on subjectivity as to be empty.

Alternatively, the oldest part of our brains provide a seemingly crude heuristic made of emotional responses that has, over eons, been remarkably refined by the time it has endured so very very long. Is it not wise to listen and often defer to the deep wisdom of our evolutionary history?

Do you have to know how you know to know that you know? To me, that is the greatest philosophical puzzle and also where 90% of the squabbles between atheists and apologists end up.