Why are you not allowed to overtake now?

You answered correctly. Overtaking is not allowed here because the cyclist ahead could turn left unexpectedly, creating a danger if you try to pass. Additionally, your view of oncoming traffic is blocked by the curve and parked vehicles, so it is not safe to start overtaking. Both reasons must be considered to ensure safety: always wait until you are sure the way is clear and the cyclist is not planning to turn. This helps prevent accidents on unclear or narrow roads.