Zed's new ult passive isn't actually good against most ADCs.
Reworked Zed kills the average ADC midgame. Their items?:
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See the problem here? Most of that damage is crit and attack speed. That is only 78 bonus AD. This means Zed only gets like 7.8 AD more than if the target just went full AP or full Tank. That doesn't even consider the fact that most ADCs have below average base AD. Almost anything except another AD assassin or Jhin yields a shitty payout for Zed.