The AI in TFT is much more of prevalence then the dev team has given it credit it seems. Currently Lissandra has very little bad spells that she throws, she 9/10 times hits the most targets or uses it on herself when low hp. This makes her a very consistent force, which in TFT, IS a big deal.
Compare that to Morde that often wastes his spell, while having clearly better angles at what to slam the enemy to get max hits.
Making a more consistent AI among all champions would balance the outcome of TFT and make it more competitive. As long as RNG/luck is heavily involved, it will stay an inferior competitive game mode.
Another thing would be to introduce fog of war after a certain amount of players have lost all hp ( when for example, 4/3/2 players are left). This would make anticipating the enemy position be a more strategic decisions, and not a quick and bothersome changing screens to constantly change your setup when its 1v1 at the end.