Quite a few good, accurate points made here by JTO et al. Perhaps I can add a bit more. If the recently graduated first UK ab initio course are anything to go by, they completed it to a very high standard and weren’t phased at all by the (almost) equal ratio of live and synthetic flying. The F35 simulator is very immersive and, to quote one student pilot: “first solo was fantastic and a bit of a non-event as it felt exactly like this simulator I did beforehand!” It’s a low risk and low cost way of getting people trained to a high standard.
Yes people joined to fly jets - and they absolutely will fly a good amount in F35 too - but much of the tactical sharpening of pilots is best served in the Sim where serious threat systems can be pitched against our tactics, techniques and procedures. It also allows pilots to gain confidence in the whole system’s capability.
It’s a different approach, that’s all. So far the feedback is wholly positive but we can veer and haul with learned experience.