2 reasons why Spider-Man 4 should be a multiversal movie (and 3 it doesn't)
Why it should: It could be the last multiversal Spider-Man film
The MCU is divided into different "sagas" depending on the overarching stories it tells. The Infinity Saga took place from the very first Iron Man movie all the way to Spider-Man: Far From Home. During that time, audiences witnessed a narrative in which the Infinity Stones had a heavily protagonistic role. Eventually, it all culminated with Tony Stark snapping his fingers and turning Thanos and his forces into dust. Ever since that moment, Marvel hasn't revisited the Infinity Stones (unless it was to make a joke about them in Loki), even if they were once very important.
On the same page, it's very likely the multiverse won't be at the heart of every single story (if any) after Avengers: Secret Wars. That's less than three years away and, during that period, we'll only get one more Spider-Man movie. It could be our last chance to watch a multiversal adventure starring the wall-crawler in a very long time. That's an opportunity that shouldn't go to waste.
We had seven Spider-Man movies in a row across three different franchises without any multiversal plot points involved. So getting two of them back-to-back could be a nice "breather" before we eventually get more street-level stories. After all, if Spider-Man 5 and 6 get made, chances are they will bring the character back to his roots as a friendly neighborhood hero. So one last wild swing filled with cameos and shocking surprises wouldn't be too bad.