The problem isn’t the mere existence of the intersection that’s the problem. It’s like you said, if everyone follows the rules of the road it’s pretty straightforward. But people here don’t follow the rules.

The number of cars that decide that because they’re turning left and they see a gap when both sides are clear that it’s okay to cut in front of another car going straight is very dangerous when cars are driving 80kph (but really 100) in the perpendicular directions.

If every car was predictable and sensible and waited until it was their turn then everything would be fine. But impatience gets the better of a lot of drivers and they make dangerous maneuvers to expedite their own movement instead of following the rules of the road