Compare that to the combustion engines who virtually have stood still since the 30's.
Not quite stood still.
Point first.
Electronic fuel controls which adjust for temp and atmospheric pressure, and injector ports and tune fuel/air mixture fine precision. (Granted, diesel engines continue to hold their own, but you cannot simply write off emissions.)
Point second: use of new alloys in engine blocks and other components, improve HP to weight. Good for cars, good for planes.
Won't proceed farther. The reliability of IC engines currently produced dwarfs reliability of even a generation ago. MTBF lower. (I specifically refer to cars here, suspect aircraft IC engines similarly improved)