Fizz's revamped Q really needs more damage. Fizz's CDs are too high, essentially, forcing him to take 40% cdr, for his AP ratios to be so low. Most mages have a lower CD spammable spell or have the safety of range to wait for CDS. Fizz does not have that luxury. The problem with comparing him to veigar is A. Veigar's ultimate is point and click. B. It's ranged, and C. It can basically 1 shot an AP by itself. Veigar has an aoe area stun. Fizz has mobility because he can't do damage if he isn't in melee, unlike every other assassin in the game that at least has poke from range from at least one ability, esp Zed. Putting the damage on the shark was a stupid move. Fizz's ult is like Zed's ult. You know how everyone says, oh it's balanced because it can be countered by zhonya's or QSS. Well shit, can't Shark be countered by Zhonyas or QSS? Why yes, yes it can. Or, since it's a skill shot, you can dodge by flashing, or by dashing or by simply dodging it. And unlike Zed's ult that puts you right next to the enemy, Fizz still has to reach his target in order to make use of it. Janna would like to have a word with you about reaching anybody. And good luck getting that shark on the ADC. The enemy tank eats fish for breakfast. And you can't use your E for damage or you have no escape, unlike our friendly neighborhood Zed who can just press R and return to whence he came.
But it's totally cool, we got AD bruiser and on hit Fizz. They also buffed bruiser fizz pretty nicely. The build that WILL land the shark is AD, since he'll be in melee AA'ing his heart out, not really needing the fish besides as a catch and slow tool or initiate. That extra damage will work nicely for him. And that W + Bortk Synergy means each AA from Fizz is going to do 8% max health pre mitigation, half physical, half magical. AD bruiser Fizz Q will do the same levels of burst as the now nerfed AP fizz, as Q has a 1.0 scaling on AD since it applies on hit effects and normal damage (essentially it's an AA). Since E is not needed for damage, he can now save it every time for a dodge, slow, gap opener or closer. He's at least as big a lane bully as his old AP self, but this time, not needing the E for damage and with sustain through lifesteal along with stronger AA's. Out of lane, Fizz will be in the front lines, causing havoc as a bruiser with still enough burst from his combo (which will include tri-force and Botrk) to nuke the ADC back to the fountain. Sit and soak damage and 1 v 3 and escape with E when things get rough? That's the new Fizz and it's been working out pretty well so far, in the top lane, in the jungle, or even in mid. It's essentially got more counterplay since you won't just be instant bursting down people, meaning people can now react and fight back, which was what Riot was trying to fix. But this isn't the fizz you are going to be able to beat in a fight lol.
The changes actually made Fizz less of an assassin and more of his secondary role, a fighter as his current AP build has too many weaknesses for it to be viable much above a 40ish% win rate higher up.