Remove smite from URF
I understand that it was left in for tactical plays at dragon or baron, but all it has ended up doing is making people think that jungling, like in a normal game, is OK. Unless the enemy team also has a jungler, then there is nothing good that comes from it.
First, your top lane now has a 1v2 situation. This is just the start, and it exacerbates the other problems. Then, in that 1v2, you often lose top tower before or soon after turret plating falls off, allowing the other top lane enemy to roam without consequence. Next, your top lane, once the tower is down, cannot do anything to move out past the inner tower, lest they be ganked.
All of these advantages just snowball into every lane getting crushed, because someone decided to jungle. There are rare circumstances, where the jungling is actually impactful, but in nearly every one of those situations, the team needs to just cling to the threads of sanity to barely stave off being crushed before jungling shows its worth. Usually the game is over before that situation come to fruition.
I have yet to experience, or hear of, an URF jungle that really turned the tide of the game (in a positive way).