My experience has been just the opposite. Must be I sim different models? Or own the wrong "real" ones.

Get a small biplane and a good crosswind. Or a downdraft at the treeline when you're coming in low. Or when you took off with 10 mph wind from the west and minutes later it is 25 mph out of the north. Also seems that someone has mowed the whole world in sims and there's never a fence or field of ragweed or corn to catch a wheel or cause a ground eddy in the low winds.

One thing an instructor can do is to teach you engine techniques. I have only played with crude sims (Dave Brown's RCFS2001 and FMS) but I don't believe they get into tuning for a good reliable run out of a glow engine. I've also never experienced a tip stall on approach with any sim model except the WWI bipes, and even then they are s l o w instead of half-a-heartbeat like some will. Also seems most sim low wings just slow down and glide forever at idle on approach (and never konk out) instead of dropping at 45º like mine seem to.