How about making it possible to actually play the game as an immobile caster vs. an assassin?

Instead of just letting them repeatedly dive you from 100% under your turret.

Just had a game as Lux vs. Fizz, where we were both 1-1-1. At level 6, he threw his ult, I flashed out of it. Two minutes late, the enemy Jarvan flashes in and ults me. I can't avoid his ult, I die, he's now 2-1-1.

Now I returned to lane and the 2-1-1 Fizz was able to dive me from 100%, without landing his E. I bound him after he missed his E and he died as well. Building MR is not doing shit. If he had landed his E, I would have still died with an extra Negatron Cloak.

I'm now 2-3-1 Lux against 3-2-1 Fizz. If at any point he manages to juke my Q, or he lands his E, I'm dead, with no counter play. It's too early for me to even consider having an hourglass, so I can't do fuck all but repeatedly die under my tower.

This is dumb as fuck. Virtually any assassin can do this if they get slightly ahead, and as an immobile caster, you can't do shit to stop their dives.