Since AD-carries are on the stronger side right now due to unintended itemization, Riot is looking into some potential changes. A Rioter has said that the company is considering making the items melee-only, so AD carries can’t use them anymore.
Both of these items were meant for AD assassins, with both items being core on Zed and Youmuu’s Ghostblade being core on Talon. However, for a while now, AD-carries like Jhin, Vayne, Lucian and Draven have been building Youmuu’s and doing work using them.
Snowballing burst champions like Jhin and Draven have also been building Duskblade of Draktharr, which deals bonus damage after fighting, similarly to Zed’s ultimate ability.
Youmuu’s Ghostblade was actually changed in patch 5.22, removing its critical strike chance and changing its recipe to be more melee-friendly. This didn’t stop it from being the first-bought item on many AD-carries. Riot then nerfed the item again in patch 6.12, reducing its amount of AD by five, but this again didn’t stop AD-carries from building it.
Youmuu’s specifically gives AD-carries a pretty solid early-game where they don’t have to rely on low crit-chance to win a fight. The item gives a good amount of attack damage, armor penetration and cooldown reduction, making the item monstrous on carries like Lucian. The active gives a boost in movement and attack speed, so popping in and assassinating somebody isn’t too hard.
Having that early armor penetration against targets that have nothing other than their base armor is brutal as well.
While many think that these changes could ruin AD-carries forever, it’s worth noting that Riot has said that they’re just considering these changes. Nothing is set in stone.