I agree about the lack of realism in the sim. I haven’t flown one yet which I thought had good fidelity for crosswind training, although I should qualify that by saying they were fine for demonstrating/practicing technique, which could be polished on the real thing.
I think it’s a combination of the lack of realistic turbulence, shear, wind gradient, backing/veering and ground effect, coupled with the sim model diverging from reality as the amount of sideslip increases. As these are the things that cause most of the problems with crosswind takeoffs and landings, it comes as no surprise that real life is somewhat different. It’s much easier to fly down the approach with a constant drift angle (which you could get away with in most of the sims I’ve tried) and plonk it on than to have to deal with all of the above at the same time.