What happened in Spider-Man: No Way Home was Scarlet Witch’s fault. A Marvel theory explains it and it makes all the sense in the world.
A theory of Spider-Man: No Way Home suggests that Scarlet Witch is behind the arrival of the Sinister Six to the Marvel Cinematic Universe. In the last movie Spidermanthe spell to erase memory cast by Doctor Strange is interrupted by peter parker. This causes the spell to spin out of control and appear to “blow up” the multiverse. The film suggests that this is what caused the villains of the old spider-webs to accidentally appear. Some villains who do not belong to the main universe of the UCM. But what if there was something else?
The theory posted by a user of Reddit argues that Scarlet Witch was the one who sent the villains to capture America Chavez. That is the plan used by the character of elizabeth olsen in Doctor Strange in the Multiverse of Madness. The truth is that it makes sense. It can be possible. According to the MCU timeline, Wanda Maximoff had already become a user of the chaos magic during the events that take place in Spider-Man: No Way Home.
This theory makes a lot of narrative sense.
Did Scarlet Witch bring the Spider-Man villians into the MCU? (No Way Home? desde MarvelTheories
Through his research and study of the dark hold at the end of WandaVisionScarlet Witch has surely tried some spells and various ways to bring her children back. Or, conversely, find a universe where she can finally be with them. During that testing phase, it is logical that she practices with less powerful beings, as is the case with the villains of Spider-Man: No Way Home.
This theory states that such an event of Spider-Man: No Way Home it may have been Scarlet Witch’s first foray into using figures from other dimensions to capture America Chavez and steal power from her. However, in this case the villain of Marvel Studios he was unable to control them, as Doctor Strange contained them within his particular memory spell. He allowed them to have some “free will.” And what could the Sinister Six do with that freedom? Well, go for Spider-Man, of course.