Why are you not allowed to overtake now?

Your answer is fully correct. The reasons why overtaking is not allowed here are:

1. The cyclist on the left side could suddenly turn off to the left. You must always expect such movements from cyclists or other road users, as they may change direction without signaling clearly or in time.
2. You cannot see oncoming traffic clearly and early enough due to the road layout and limited visibility (e.g., around the corner, parked vehicles). This means overtaking could lead you directly into the path of an oncoming vehicle, which is dangerous.

The poor condition of the left-side road surface (option 3) does not legally prohibit overtaking here. The main safety reasons are the potential cyclist turning and obstructed visibility of oncoming traffic.

In summary, overtaking in situations where you cannot judge the safety due to turning cyclists or poor visibility is prohibited to prevent accidents. Always wait until you have clear sight and the road is free from unpredictable hazards before overtaking.