Zyra Plant AI
Years ago in a patch it was made so that Zyra's plants wouldn't prioritize champs. I still can't think of a good reason for this but it feels like, with all the other AI driven mechanics that have been added since then, Zyra has been left behind both mechanically and in outright power in teamfights because her main source of damage is looking for minions to kill in a teamfights setting once you've died. It would be an easy fix to revert the change and restore Zyra to modernity.