The ers-saving AI excuse proves that this isn't realistic.
AI doesn't need ers to attack? nor to defend themselves? in this logic not seen that all the AI save the ers, but you also forget that in the last lap the tires are dead so the AI is supposed to be slower than its fastest lap, so the ers will just help to be a little faster in a straight line, the tires being dead, there is less grip but in the bends the tires prevent them from rolling very/too fast so the ers do not change anything.
I persist that the AI has a * god mode in the last lap and also in the pit lane exit laps does not have as much problem with cold tires.
EA is their legendary script we still hit.