Veigar has absolutely no escapes and has to farm up his AP which means every time he uses his Q to farm minions he's gonna be down 1 ability if his laner decides to all-in him. Like don't even give me that shitty excuse lol, he's easily stoppable early game. I legit play him because of this cancerous Tank meta anyway. How else do you stop a tank with 4k health, 200 mr armor from 1v5'ing your team purely from outsustain and somehow magically having dps as much as your average midlaner. Veigar is the Jesus fucking Christ solution for anti-tanks right now.
Like to put it into dumbed-down words for you to understand: He has ZERO mobility, absolutely** NO** presence in the early game which means he's campable and outroamable. Unlike Energy champs or champs with no mana bars, he's actually easily killable if you see his mana bar low, which chances are.. he will be from farming AP.
Like I'm completely fine with his kit the way it is purely because other mages have the mobility to outplay him. Here's some example counterplays vs. Veigar to give you an idea:
-Ahri has a 3-fllash ulti on hardly any cooldown.
-TF can just say fuck laning vs. Veigar go snowball off other lanes from ulti teleporting.
-Xerath and Lux don't even need to be in Veigar's short range to farm or poke him out of lane.
-Zed/Yasuo/Katarina/Vlad don't even have a fucking mana bar.
-Fizz/Ekko can completely negate his abilities with invincibility-frames.
-Vladimir is going to completely outsustain you whenever ignite is on cooldown early game.
-Kassadin and Leblanc: good luck actually landing Wall vs them when they jump. Not to mention Kassadin is THE anti-mage with his passive and Q shield.
-Malzahar: built-in banshee's veil passive and forces you to buy a QSS (doesn't even build into AP or neutral tanky item, so you're set back 1300g in lanephase).
-Orianna has superior zoning vs Veigar early game.
-New Swain is actual cancer now in laning phase as Veigar with no boots before 1rst back.
-Syndra doesn't even need to be in Veigar's attacking range to use her knockback stun initiation.
-Viktor doesn't need to be in his range to use his pizz lazer.
-Azir doesn't need to be in his range to send soldiers flying at him.
-Anivia doesn't even need to give a fuck about dealing with Veigar, just waveclear with 2 seconds of R up.
-Galio has enough cc's and jumps to be considered a fucking Battlerite character.
-Talon is just going to jump over 2-3 walls because a no-mobility no-jump Veigar can't followup should that hexdrinker proc and Talon manages to live with low health.
-Annie stun is instant so she wins trades whenever her Flash is up by default.
-Morgana outpushes him with simply 2 W's and can completely tell Veigar to fuck off with her spellshield.
Do I need to give any more examples of how to outplay Veigar?
Sure he's a nuke, but he's got no mobility, 1 flash Vi ulti, flash malph ulti, flash ahri charm, flash tank cc engage in general and he's screwed. Hell once Olaf hits level 6 his Wall is a joke. Good luck self-peeling vs. that with ZERO mobility.
#Note: I'm not implying these matchups make it impossible for a good Veigar to still outplay though as I know all the counters to these matchups as well. I'm simply listing these to show you all the ways to deal with Veigar due to his lack of mobility and early mana costs when deciding to AP farm.