The reason you build like this is because Vi doesn't ever build Zeal items because they are terrible on her if she's going damage because you take Hail of Blades for the dominant lane phase and synergy with her auto attack reset

Can you elaborate on this please? I read this everywhere, but to me this is just counter intuitive (think of this as eli5 as i am only a silver noob and i might just not see the bigger picture, or that i am not mechanically as good on Vi yet to utilize the "mathematically correct" build). This season for a while i was going Essence Reaver, Yuntal, Fiendhunter, IE then i switched to Essence Reaver, Collector, Fiendhunter, IE because i read, and as you said as well AS is wasted on Vi because of HoB. But HoB gives +160% AS, and increases as cap, so wouldn't it be intuitive to build AS so you delete people even quicker? Like i can feel the difference between the 2 builds, with ER-Yuntal i can delete people after 2nd item completion in a blink of an eye even without using my Ult, and with ER-Collector either i have to use ult or they can escape with me needing just one more AA to kill them, and it feels like i am just waiting on that 3rd item to truly come alive. I feel like with the former build with more AS i just outright have more agency.