Due to Peter overhearing Doctor Strange’s (Benedict Cumberbatch) spell, Spider-Man villains from other universes are dragged into the MCU timeline. Those who know Spider-Man’s true identity all come across, which is the opposite effect of what the spell was intended for. The film’s ending reveals that there could be countless people who know Spider-Man’s identity. They’re all from other universes, but the only ones that really make it through are characters who’ve been in the various “Spider-Man” movies. Sure, Vulture knows Spider-Man’s identity, but he’s already in this universe, so he doesn’t fit the villain requirements to play a big part in “No Way Home.” As far as we know, Vulture is still in prison.
However, to make things more confusing, some versions of Vulture will be in the upcoming Sony movie “Morbius”. Michael Keaton appears in two trailers as Adrian Toomes, speaking to Dr. Morbius. Based on The Hollywood Reporter, he’s playing Vulture in the movie, but it looks like “Morbius” isn’t taking place in the MCU. Instead, it exists in the same universe as “Venom”, which is certainly different from the MCU. “Venom: Let There Be Carnage” and Credits for scenes from “Spider-Man: No Way Home” depicts Eddie Brock (Tom Hardy) being transported between the two universes, but it looks like he’s back to his original self this time around.
So we’ll see Vulture in the future, but “No Way Home” has been too busy with multiverse villains to deal with someone from this universe.
https://www.looper.com/711751/why-didnt-we-see-vulture-in-spider-man-no-way-home/ Why don’t we see Vultures in Spider-Man: No Way Home?