Sims are great for practicing drills and I have no problem with that, but sims will never replicate real flying.
There will always be situations where the event was never covered in the Sim and it is only real hands on that will allow a pilot to get around the unexpected, because that is where experience will be gained. If you don’t fly for real, is it really worth spending all that money if the outcome could be 50:50 (because your opponent is not playing as programmed)?
Plus, at the end of the day, are you going to send an aircraft to fight an adversary if the computed outcome says you are going to lose?
You need pilots who are capable of doing the unexpected, which is only achieved by flying for real and gaining experience, otherwise we might be better of deciding war by playing a game of Risk. It would certainly be cheaper!