From what the mother said before she died and the behavior of Gosling's character with a prostitute, I understood the essence of this whole mess. A mother has two sons, both in love with her as a woman. The eldest son lives with her like a mistress. The youngest is jealous not only of her brother, but also of her father. He kills his father with his bare hands and escapes to Thailand.
Billy's eldest son is also in Thailand. But he is already mentally crippled by his mother, so he cannot have sex with an adult prostitute and asks the girl. There is no girl, and the woman did not work out and, having gone crazy, Billy kills a prostitute.
And then they actually kill him.
If these circumstances were known to the viewer as a prologue, then the film would be perceived quite differently.
In fact, I did not play a spoiler, because what I reported is not explicitly in the film. And Refn failed to submit this to give a semantic load to the viewer. So you watch the whole movie as a set of peeping and bloodletting scenes.
But I love Refna as a director. I enjoyed the movie even though I didn’t know what was going on. I only got the point in the final.