I've noticed a trend awhile back that people kinda brushed off.
The top 6 top laners in pick rate all rush Black Cleaver first. Can we stop pretending that the item is balanced and add some more diversity to bruiser itemization.
Source: https://www.op.gg/champion/statistics
The %pen nerf didn't really hit the mark because the champions can easily get the stacks and start long trading you without much damage lost in the trades.
The base stats the item gives is already 100% gold efficient with 4 long swords and 2 kindle gems (regardless that the CDR is unique passive on KG). This isn't even including the MS and %pen passives on it.