This was the farthest humans ever travelled from earth, even farther than apollo 13. Intuitively the farther you go the higher the risks are

Landing on the moon is enormously riskier than simply going further out.

I'm answering the claim about Artemis being more dangerous than the space shuttle. Obviously landing on the moon is a lot riskier.

They could go twice the same distance, the risk would be roughly the same at that point. It's mostly the complexity and changes that make it more risky once the initial trajectory is in place.

You need a lot more impulse and more fuel to go twice as far. Probably more correction burns. A longer final burn before entering the atmosphere. So the risk of loosing the engine is much higher and probably increasing more than linear with burn time/change of impulse.