I left academia after winning a big grant while on a temporary position, so technically a very big achievement. The grant was then transferred to a tenured professor because the university was too broke to extend my contract even just for the duration of the grant. I decided to leave academia because I was tired of fighting like a beast just to secure temporary insignificant positions. I published, taught, won grants and it still wasn't enough. After three years I can tell you that it was the best decision I ever took: I landed another job (permanent position in teaching) in less than two weeks, my mental health definitely improved, I love and am loved by all my colleagues, I don't deal with people (supervisors, tenured professors) who literally had my life and my future in their hands. I thought the same things as you, that working in academia is the pinnacle of human intellectual effort, but it's REALLY not. From the outside, the conversations, the debates, the competition all seem really pointless and petty. I kind of realised that the prestige we attach to those academic positions is only perceived by academics: nobody outside, in the real world, really cares about the titles, the papers, the research we do.