This has really bugged me since the start of fs2024. This is what you see in videos due to strobing between the propellers and the frame rate, and certainly not what you see in real life.
It is not just the unrealistic visual effect, but the amount of computer power it must take to compute the shadow (in the cockpit, on the ground on the wings etc.) of every propeller blade on each propeller many times per second. This is likely to be a contributory factor in the low FPS I get on the relevant planes (eg TBM930) compared with airliners or the Pilatus PC-24 for example, which have far more complex dashboards but better FPS.
I have already submitted this as a question in the upcoming dev stream.