Triforce and very mobile champions - taking towers too fast
Now that Triforce and other bruisers are back in the meta, it's very hard to roam and actually help your team.
Add that on top of weaker towers, we have an environment where when someone snowballs.. you completely lose the game.
The team that tries to help the guys that are behind tend to die also, and on top of that they give up the towers.. also putting them behind. Then the enemy team just dominates and takes all of the infernal drakes lol