Riot basically also nerfed alot of the high range and burst mages (Gragas, Ziggs), so they aren't as strong too. Hence we're seeing more utility mids like Lulu, Soraka and Orianna picked. But I still feel both Ziggs and assassins are viable (Gragas pretty much isn't really great at anything anymore).
But yea, just keep trying champs until you find those you like. I personally play my comfort picks way better than the current meta OP champs~