New runes - Huge concern

Looking through the new runes I saw that there are zero lethality and magic penetration rune options. This is very concerning, as penetration is very important on assassins specially magic damage ones and liandry's is not an item that has synergy with many AP assassins, which leaves them only with sorcs, which very often is not enough + makes sorcs a must have item locking them out of other boot options. This is an even bigger concern now that Riot gave free scaling MR to all ranged champs.