Now, for the spoilery observations.
The Elementals are a sham - the movie is entirely about Peter trying to balance his personal life with the expectations of being a superhero, and living up to the legacy of Tony Stark. Just about everywhere in the movie is some painting on the wall of Tony’s or Iron Man’s face, looking down at Peter - who just wants to enjoy a vacation with his friends, and tell MJ that he really likes her.
Quentin Beck/Mysterio is the front man for a group of disgruntled former Stark employees, who felt snubbed by Tony. They determine to get the notice and fame they feel they deserve by manufacturing a crisis, and having Mysterio swoop in and save the day. Shades of Syndrome from the Incredibles movie.
The post-Snap world (referred to in the movie as The Blip) is rather lightly touched on; May refers to popping back in to an already reoccupied apartment, for example. Mostly, it’s played for laughs. I get why they did this; the movie is fast and cheerful, and dwelling on the problems of the Blip would have distracted from this and the main theme of the movie. That being, I think, the conflict between personal desires and societal duty.
Throughout the movie, I’d thought both Fury and Hill were being rather credulous of Beck and his claims, and acting a little oddly as well. Very obvious in their machinations, reactive in their actions, with relatively little in the way of planning. Turns out there’s a reason - they were Skrull impersonators all along, specifically Talos and his mate. Fury had spent the whole movie up in space, as revealed in the end credits scene, on what looks like a Skrull-crewed spaceship.
Yah. Like I said, major implications.
Overall, I enjoyed it quite a bit. The adolescent bits were well-handled; I rarely have much patience for all of that, but they made it charming. Performances were generally good, though characters like the teachers were largely one-note caricatures. Pity, but the movie didn’t have much time for them, and that’s fine.
Not the very best MCU movie, not quite as good (IMO) as Into the Spider-Verse, but still well worth a watch. 8/10.