Can we buff Annie's late game

I can easily burst champions down early on and in the middle of the game, but once champions reach level 17 and 18, however, Annie is literally useless. Her ap ratios are decent but can't scale with any passive, unlike ryze, vladimir, and veigar. She doesn't have much health even with RoA and gets focused and killed before she can get anything done. Why is veigar allowed to have infinite scaling but not Annie? Until this is adressed, I'll only be able to play Annie as a support.