When someone else was paying I was happy to fly up front but when I pay I can be pretty stingy. Now in retirement for sure I fly coach if less than 6 hours. Over that and I might consider it. Last few years before Covid I was flying back and forth to southern Africa two or three times a year and the return flight was 15 hours on the plane - that one I upgrade! When I first started flying there in the the late 80s flying coach wasn't so tough as one often got a row of seats to oneself on a 747.