The Sopranos wasn't realistic, either. Tony, a boss, committing murders, making collections beating people, etc.

There's a difference between "realism" and "reality". Realism only needs plausibility. Could this person do something like this, etc. Not whether some of their stature would do it, but just whether it's something they would do, personally. They have Tony killing people to show the audience how bad he is. Because much of the show includes his wife and children. If they never had him commit a murder, the audience would be left to wonder whether he really is that bad. Garroting someone on his daughter's college trip leaves no doubt. Just like they show Junior present for the Palmice hit. Not realistic, but shows the realism as to what Junior is capable of morally. He's not just some grouchy old man who runs a couple of unions and sports books. He's a killer.