Why was zehpyr removed? or tenacity?

If I had to guess, due to the item's low purchase rate , riot made the conscious decision to completely remove the item rather than improve its build path. Sure, the fact that the item provides both tentacity and attack speed would've made it a viable item for adcs in the pre-season meta but ADCs still have the choice to build to mitigate CCs. Didn't seem necessary to keep the item.