Neji's a great tank for damage teams. Since the battle tends to be short, you only need a tank on turn 1. On turn 1 he Taunts and spins like Hinata without costing you any chakra. Plus he can stop jutsu. Or you c*e him in a later turn to stop a jutsu and since he's the position 1 character he's insanely fast at interrupting.
He's a tank that becomes utility later, unlike someone like Hinata that dies or becomes useless when having a tank no longer matters because jutsu are getting hurled around.
Plus he combos quite well with a lot of mains. He can't acupuncture like Hinata but High Float is easier to combo off of with damage teams.