[{quoted}](name=My Waifu Vanilla,realm=NA,application-id=3ErqAdtq,discussion-id=AdZ3E44f,comment-id=0000000000000000000000000000,timestamp=2018-09-24T13:45:33.162+0000)
Except it isnt. I get more damage from a BF Sword which costs half as much. We live in a world where you're better off maximizing damage so you dont NEED CDR. If someone like Zed NEEDS the phage passive to run someone down with autos then he isnt doing his job right.
Remember, it’s not just any one effect but all of them combined that makes Black Cleaver so good. It’s gold and slot efficient. Now, on to your points.
BF Sword does not give more damage than Black Cleaver. BF gives 40 AD while Black Cleaver gives 55. It does give 15 more AD than Phage—but costs more and grants no health or passives.
Also, even when damage is high, Health on a melee champion is crucial. It lets you shrug off poke and survive all-ins. Guardian Angel gives you Armor, but its pricey passive procs only once every 240 seconds.
Another thing is someone like Zed blows as putting BC stacks on tanks. He can stack it on a squishy fine, but it takes way too much commitment to stack a tank since you're throwing abilities at them instead of you know....at the ADC that is now free shooting you and going to kill you in 5 autos. Talon is slightly different since he is much more AoE focused and can send stray armor shreds around with his W and R, but the item still isnt good. It hasn't been good since they gutted the AD you get.
The Cleaver stacks on AOE are just nice to have. The real advantage of the shred is that landing each of your abilities and attacks increases the penetration of the next one. Even a 10% Shred from landing two abilities and a basic attack is no joke, especially when your ultimate gets to use it.