Triumph is one of the biggest contributing factors to the snowball meta

Triumph Precision Slot 1

Passive: Champion takedowns, after a 1-second delay, restore 12% of your missing health and grant an additional 20 Gold.

This rune single handedly ruins otherwise even trades and pays off bad overextension resulting in minion aggro. Instead of this bad overextension resulting in a trade and thus, mostly even lane, it results in a free tower dive or DoT trade without consequence.

Add on top of this the bonus 20g that ruins the entire point of the bounty system.

The damage creep is bad enough in the game, but the real kicker is that there are no bad exchanges whenever Triumph is involved, which it usually is because Precision grants far and away more gold of stats than the other trees and has busted keystones like Conquerer and Fleet Footwork.

The rune not only invalidates the other two in its slot, it invalidates any rune in the other slots and were it not for the stat splitting, would strictly invalidate the other rune trees as well.