There are many things that go into winning a basketball game. But at the core of the game, you have to score more points than the opposing team. Scoring is one of the most important skills in basketball, and the ability to get buckets in a variety of ways is crucial to being a good scorer.
Gilbert Arenas was an elite scoring guard, averaging 29.3 PPG during his best individual scoring season. He has recently put out a top 5 list of the best pure scorers to play the game. The list included Michael Jordan, Kobe Bryant, Allen Iverson, Kevin Durant, and Carmelo Anthony. (2:03:40)
I gotta be biased because I can only go as far as I watched the game. Jordan, Kobe... Kevin Durant, AI... I can't sleep on Melo.
All five players are either already in the Hall of Fame, or they will likely be inducted after their careers are over. Each of them has won at least one scoring title in the league, as they were often the offensive focus on their teams. Sometimes roster construction puts you in a position where you have to absolutely carry your team's scoring offensively.
Having a good scorer is often very beneficial to any team. In a playoff setting, you need players who can get you guaranteed points, often against top defenses. Some players are built for those moments. There is no argument that the players that Arenas mentions are all-time scorers: while others may have a different list, Arenas was definitely fair in his selections.