Game Length has been killed

I have played several games in this new preseason and one of the most under reported changes that I have noticed would be that game length has been changed. What I mean by this is that most of my games have been running at 20 min since this preseason started and most of my previous games before the patch were 30-40 min. This results in a massive nerf to late game champions that need time to scale and it kills several of the new runes that were introduced. An example of this would be the conditioning rune. Why would I take that rune when the game is decided in the first 10 min? This needs to be addressed or champions and runes will stagnate in state like Aatrox prior to his more recent changes.