i dunno why people hammer on one pick when watching competitive. all picks in competitive are based on having little to no counter and on being as "abusable" as possible. like ziggs, lebonk, gragas, zed, ahri, orianna, khazix, elise, caitlyn, lucian, thresh, shyvanna, morgana, they're all broken in some way that's awful when played to the most competitive level
but in a real game like ranked or something a lot of those are really ok. i don't really mind gragas, most people don't play him or don't play him well enough (myself included on the second one) so he doesn't bother me so much. unlike ziggs which was fotm not too long ago.
plus while grago is pretty op he at least has a shred of a weakness like being melee or having not much sustained damage. nidalee has her shit laning and is very feast or famine depending on if she gets farmed. lebonk can't waveclear for shit and is very snowball reliant. ziggs really has no weakness, he's waveclear, poke, burst, semi-global ult, free lich bane thing, strong early game, strong scaling, aoe damage and cc.
so yea for me personally ziggs is the most annoying midlaner right now, with yasuo contesting thanks to his stupidly broken ult shield and just annoying kit overall.