I just don't agree. If you design a structure in aluminum, fatigue can certainly be an issue. It means you need to acknowledge the fatigue and design with numbers that represent the part's strength after millions of load cycles.
Every structure designed has fatigue figured in regardless of material, it is not exclusive to aluminum and nonsense to stand it out to need more consideration in design from others. It is exactly the same design process.
I wouldn't think that aluminum connecting rods are optimum, where there are gazillions of cycles and relatively predictable stresses.
Triumph and BSA motorcycles were the 2 leading motorcycle brands in the world up till the 1970's and the bulk of them used aluminum rods (and pushrods), so regardless of what figures you offer up, some of the world's leading engineers disagreed with you.
Not sure if you guys are into dirt bikes but when Honda released their first aluminum framed motocross bikes in the late 90's, the panic and hysteria was hilarious. Amazing since they came from one of the largest and leading automotive engineering companies in the world. Even today when a KTM or Yamaha frame cracks "aluminum fatigue" is blamed totally ignoring the amount of steel frames that break.
The list of extreme stress aluminum in daily lives is extensive, MX bikes, planes, ocean going fishing boats, etc. yet the myths persist.