Gnar still outdamages any melee toplaner before getting
because of how MUCH damage he can deal...
The Armor shred for Gnar also boosts his ability to deal damage AND his ability to kite by stupidly high amounts of stats
Gnar gets the best of an abusive earlygame, an amazing midgame, and an insane lategame for basically NO cost
"he's unreliable", well his cooldowns in mini-form just mean one team has to stall for 30 seconds until he spams Q enough for mega-Gnar and the team with Mega-Gnar wins every teamfight(for the most part)
Gnar's "weaknesses" are basically non-existent in the toplane
Similar to how Akali craps on toplaners because she outtrades and outscales every non-tank toplaner, Gnar is in the same boat
The two are only able to lose to champs that have movesets that completely counter them in order for them to be countered properly
The actual skill of the players involved is a factor that barely matters for Gnar players and Akali players