Champ Diversity
I think Riot really made a solid improvement to the Esports scene when they implemented the 5 ban system. Champ diversity has really begun to show. Just in the spring split, we've seen Shaco, Draven, Talon, Katarina, Mord, Ziggs and others. While some of those champs like ziggs were played because people have recently found ziggs to be really good in the bottom lane, I feel like the 5 ban system still helps with him seeing the Rift in the Esports scene.
Also, the standard champion pools for each position have also increased. For example, last year top lane had a pretty small champion pool, with the same four or five champions being either picked or banned. This year, we have Camille, Shen, Maokai (Even after his nerfs he's still been played a tad), Nautilus, Renekton, Rumble, Fiora, Ekko and an argument could be made for Gnar. That's nine champions that are cycled through in the top lane. The 5 ban system has expanded the common champion pools for each position.
In short, the 5 ban system has brought a ton more diversity to the competitive League scene and I hope to see that continue.