I feel useless as a Mage when the enemy team comp has more than one tank
Lets say this is the enemy team comp:
(this is a pretty standard comp)
Lets say im playing one of these mages:

Now lets see, what are my options?
Well,
can just buy hexdrinker+black cleaver and then they basically cant die to me, and theyre too mobile for me to catch in the first place (plus if i go near them ill get oneshot)
And
will just hide under
so i have 0 kill potential on them also
And lets not pretend that mages even have an effect on 
So now what am i supposed to do? Buy support items and be a secondary support? I just feel like mages have no kill potential in this current meta. Give AP some love, riot.

, just incase they had a DPS mage.
if they have even one tank. Dont doubt them especially
all fine choices for ADCs and they esch have anti-burst passives
(to resist an abilify)
, the true damage Mage.
= 30 magic pen