I remember running full %mana per level runes on AP Kog'Maw in S6

Right before they runed (ruined) the rune system I would do crazy, unique builds where I'd run full %mana per level runes or when Kog'Maw jg was a thing I would run FULL (no AD or armor or MR whatsoever) attack speed runes because I believed in what I was capable of with the champion. These options was honestly what made my gameplay so unique and fine tailored. Sure, someone could copy my rune setup and masteries but they wouldn't necessarily be able to execute wave clearing or mana management or kiting in the jungle. The mastery options were fine tailored for me, something I could go into the game with that I had completely customized to fit MY style of gameplay. When rune builds didn't necessarily work out in a game, I would be able to take note of what I was lacking and fine tune the build even more. I really missed being able to do that.

Now, I only have access to some raw stats. And in the small assortment of stats, there are some that heavily outweigh the others. Not only is there a lack of options, you're almost forced to choose specific stats over others because they're blatantly superior. In the old system there were general rune setups that were more or less optimal, that you could quickly make and hop into a game and they would help out. Currently, the runes feel so absent and useless. You could play a game without the rune shards and you really wouldn't be able to tell if you had them or not. They have no impact on how you play the game. Old runes were very polar in terms of which portion of the game you'd be investing in. Assassins could choose armor penetration for the early game if you had wonderful level 2 (like Talon). But they weren't forced to choose armor penetration because they had other options like exp runes to cheese level 2, AD runes if they weren't sure about being able to capitalize in the early game, and so on.

Riot has more than enough money to no longer have to sell rune pages. They need to bring back the fine tuning that the old rune system had WHILE retaining the current display.