L. Vonn is incredible because she got most of her World Cup wins (83) in the speed events - Downhill and Super G that just take raw courage. These are the events that you hit 75 to 80 mph, and you have the serious injuries, and God knows, she did. A racer has a better chance of avoiding injury in the Tech events, where they don't reach those speeds.
I love it that Mikaela Shiffrin is not afraid to step out of her Tech specialty, and compete in downhill and Super G every now and then - she has won four DH now. I am sure she is advised not to do it because of the chance of injury. I don't think she has had a serious injury.
Shiffrin is the most successful skier of all time, and I am a huge fan of hers because in addition, she handles herself so well. A good person.
I don't think anyone can be called the greatest skier of all time. If you had to name one, closest to it at this point is L. Vonn, in my opinion. There is a documentary about her called 'Last Season', I think. The pain she has experienced, and the numerous surgeries she has recovered from is unbelievable.