It was also because of the track where Redbull excels in such tracks,super fast ones.Ferrari only lately with the new upgrade have improved their top speed but still not enough to fight with a Redbull.
Someone was asking in another thread,is better to be 10 seconds ahead with a slower car or 20 seconds behind with a faster car,of course the answer to this after the last couple of races is to be even more than 20 seconds behind with the fastest car as it will net you the win.This Championship is over now and it will be boring for these last races,most likely Redbull will win them all.
Obviously it is better to have a much better car and be 20 seconds behind, if the difference between the cars is not that much of a problem then being in front is of course better, but the difference here was so much that even medium tire red bull would be faster than the soft tire Ferrari which was the problem.
I mean lets give the credit where it is due, normally I find Ferrari team to be the responsible party for the situation and they make a mistake but this time around it was literally the car that got the win. Red Bull had a much better car for this race and even without safety car they would be much further ahead and the difference would be insane, there is no way Charles would have won.