People say this a lot, but I haven't seen/heard a response from Riot on this.
Rift Herald exists.
The demolish rune is really strong against towers with split-pushers like Nasus and Yorick who just delete them now.
A lot of attack speed steroids. ADCs, especially ones like Jinx, can go ham on towers.
Mid-laners have good wave clear and minions aren't really defending much.
Mountain Drake and Infernal Drake(though indirectly causes more damage to towers)
Towers just need more resistances in general. Perhaps scaling the power difference between different tower tiers. Tier can remain the same but tier 2 is much tankier than tier 1 and tier 3 is the strongest protecting the inhibitor and nexus. To make them tankier, perhaps a shield they must get through before actually doing significant damage.
I say this because games end really fast now and super minions spawn so fast it's hard to really turn things around. Can't really shred a super-minion as well as you can at 15 minutes since there aren't really items.