I am one of this forum’s “grumpy old men” but before I became one I spent 4000+ hours in rear cockpits and then 15 years in the simulator business. I know little about the capabilities and tactics of future combat air systems but whatever they are I reckon an absolute minimum of one real sortie a week is required to keep in touch with the real world and to maintain the level of awareness of danger that no sim will ever replicate. During my time instructing in a very capable modern simulator I can honestly say that I never once saw a crew put in the same level of planning, concentration and commitment that goes into a live sortie.
Another point that rarely gets mentioned in this debate is that people do not join as aircrew, and put in all that toil and tears through training, to spend their life in a simulator. If that is how careers turns out they may well not join in the first place or stay in if they do.