Champ is too slow/lacking sticking power.
I feel like the only time I can fight in lane is when the enemy allows me to and then I get the reward of just being a worse Darius in the same situation. So much less lane pressure and way easier to kite out. Also any champ with a decent stun or slow can short trade you to shit and never let you figth back. The only thing Sett is good at is teamfighting but if he gets stunned on the engage he just gets walked away from again. I like Sett's kit but I feel I'm handicapping myself picking him.