We have a similar problem in the U.S. Only here it is official bribery. The police officers stop your car and ask for the insurance papers. If you don’t have them, they write a citation. You take your citation to the court house and see a traffic judge. The judge sets a fine which you have to pay to the court clerk.
Whilst neither the clerk, judge, nor officer receive direct cash, their departments are directly funded by the fines. In the background the city manager discretely tells the chief of police that the budget is rather tight and that if the police officers don’t increase the revenue collected from fines, there must be reductions. Of course this is illegal, so it must never happen. But somehow the police officers know what to do.
The leaders in the US are very corrupt, and they don’t tolerate any competition outside of official channels.