Why are people still banning Darius?

Only certain tops can kite, and Darius is pretty mean in lane.

Don't assume all bans are based around team fight phase

this may come as a surprise but not every person plays teemo and gnar

I often ban Fiddlesticks simply because I don't want to play against him. Is it likely I'd be against him? No, but I don't want to take that chance when I'm not feeling like facing Fiddle.

I also often ban champions who are good at diving like Vi. I don't have many heavy CC champions in my champion pool, so peeling is difficult for me later on.

The point here is that bans are not always about removing the six most OP champs from the match. Every champion can be dealt with, however bans allow you to not have to deal with a few of them if you don't want to. You just have to put a little thought into it.

Kite? Most Tops are melee fighters, and very few can actually give Darius trouble. I suggest you look at Top lane pick rates, because , , , and have some of the lowest overall top lane picks in general as far as anyone that counters him. Plus his Q does more damage further away than closer, heals him, and his ult is no laughing matter.