Since you've artificially given every champion more damage with runes, Riot:

how about you add some artificial health to the game as well?

And give turrets some indirect TLC?

Basically anything that makes turrets harder to kill or makes players occasionally harder to kill that isn't a freaking Zhonya's active.

Also a finished item that is simply the old Fortify summoner on a stick, even for just one tower.

Green Buff: Spawns in place of a small jungle camp after it's cleared twice in the same jungle (a green circle indicator will show up until it spawns). Lasts half as long as red/blue buff. Gives temporary max health and bonus hp regen to the player that clears it and bonus regen to all nearby units and turrets.

Ohmbringer: The current Ohmwrecker's stats (maybe a bit more health?) but with Fortify for a single turret as a global active with a 300 second cooldown. Also delete Ohmwrecker because nobody ever liked it.