Advantages of playing an Assassin over a mage:

Mages tend to have better utility, safety, and the ability to build more defensively. Assassins tend to have much higher damage output and great all in potential.

Le Blanc is an assassin, not a mage.

non besides more damage for most likely getting murdered for it

way more single target damage at the risk of being countered.

I don't feel more skilled than I really am when I get a kill on Malzahar... So there is always that :B