Runes are too important, items don't matter - an opinion
I won't pretend the old rune system was good. It wasn't. It sucked in all possible ways. But the up shot was there was not an insane difference between taking the right/wrong rune page. Conversely, if Jhin takes Resolve as his main tree, he's got a better chance helping us by DCing.
Conversely, items don't have enough expanse. You can build whatever you want, but it's use isn't really there. If a tank builds damage, he doesn't sacrifice tankiness for damage, he just sucks at both. If a mage goes tanky, she's not a juggernaught with weak spells, she's considered a troll, and treated as such, and is largely ineffective. I'm starting to think this is a problem.
I'd never really considered it before, but with the (justified) ADC nerf, I've noticed the opportunity for them to be more utility than glass cannon isn't available. And part of this is the reason champs need reworks. Yes, if you design a bad kit you have to nerf until rework. But in the champs that are just low-totem pole, allowing items in game to provide wider latitude might make for some fun new experimentation that we haven't seen before.
then yeah your going to fail.. there were "optimal" runes but there were plenty of sets that worked