I got beaten by a tryhard Gragas in top lane so it's customary that I complain

To be honest, that champion could also be considered for the definition of anti-melee. His passive is a reasonably sized instant heal on a low CD. Q is near impossible to miss with high base damage and functions as a zoning tool. W is free damage reduction and has rather high damage. E is basically a fk you to any melee champion who tries to engage with a dash towards him.

For a tank, he's got rather reliable tools, for an ap bruiser, he's got extremely nice base stats and base damage.

He may not be popular, but facing him is more cancer than Tahm Kench.