Why does gathering storm still exist?

The fact riot hasn't done something with that slot seems odd to me as Gathering Storm seems like a bit of a joke right now. Games are decided before the 20 minute mark and I don't think that the rune is really viable before 30 minutes. That means the game still has to be winnable at the 30 minute mark to justify taking this rune. Does riot have any plans to make games go that long again where the outcome hasn't been decided?

If so, I'm not seeing it.

So why does the rune still exist? If you are behind at 20 minutes, that 24 AP isn't really going to do anything. If your team is already winning by then, it's not like it did anything but you get extra stats now. This seems like the definition of win more. I'm not sure even AP supports would like it just because the game is so early-game focused you'd need that little damage from scorch more in laning than you would need from the ziltch that GS gives you in the first critical 10 minutes of the game.

Now if you got an extra minute of value every time a teammate dies, then this rune might actually be interesting in terms of gameplay because then it'd act as a negative feedback loop, something I feel like league needs slightly more of. For instance if you are in you promos, you'd know to take it because everyone on your team is going to feed for the next 3-5 games.

It just seems like since riot is pushing faster and faster games on us, they should probably give us runes that reflect the current reality of league. If the average game is decided at the 12 minute mark, then chances are that the 8 AP you got 2 minutes ago didn't really affect things at all.