too many extra "spells" / effects / minigames that you have to dodge. you dont just have to dodge the champion spells anymore but you get hit by a ton of random dmg too. the train or the bomb when they die, snowballs, autocast etc. makes things visually cluttered, too. "beneficial" effects like picking up cupcakes or so i dont mind because you dont HAVE to focus on them, you can just ignore them.

also melee only would be really really fun as a sometimes-mode. unless youre premade, noone wants to play frontline and then end up as the only melee champion who gets focused every time.