Geez, you guys are harsh. I thought it was pretty good. It is basically No Way Home Part 2. If you didn't see No Way Home, you lose a lot. It's also very odd how much it ignores the rest of MCU Spideys stories and any Avengers stuff is kept to a minimum. Someone mentioned here there was no forward progress. I'd argue that's not true. There's just very slow progress.
Let's start with the big one- what did I think about Jean Grey? Very little. Did they ruin her? No more than Marvel comics, Sophie Turner, Doomsday leaks and Last Stand already have. Who and what she is gets very downplayed. Honestly you could replace her with any generic psychic powered villain/hero. Yeah, it's setup for later but the movie does a good job of making it focused on this movie only. It's very much a prequel to the character. I'm fine with her being Talk No Jutsud though, because at least it's built up. However, there is ONE instance where they probably should've cut where Spider-Man goes "You're not a killer!", except earlier in the movie before her reveal, she possesses some guy and put him in front of a moving car have him get turned into a road pizza. Probably should've cut that lol.
As far as MJ goes, she's not nearly as bad in this one. Largely because the script actually gives her real material to work with. She does a decent enough job and is far less insufferable. What is insufferable though is the way everyone else treats her and how everyone is up her butt. That I didn't care for and found very odd. While the movie does put her back into the fold, it also holds back enough and leaves the door open to move on from her as the love interest, if they choose to do so. Which is something I'd appreciate because Zendaya 's big speech in this is a pretty good exit for the character to take on a more friend role. I'm personally glad they left it open ended and it feels more in line with the rest of the movie of things changing. If this is the end for Zendaya MJ, good riddance and she'd end on a good note.
As far as Peter's mutation thing going on, I like this far better than any of the other incarnations we got of this. I'm not going to pretend like the Man-Spider/Peter Cocoon storyline was ever good in any iteration. It was always a very stupid idea and I don't think it was done well in any form of media. At least this feels a lot more justifiable given everything this Peter has been through.
The action is also really darn good and while no villains get any real consequence or significance, the fight scenes are pretty good.
I don't know what else to say, calling it No Way Home Part 2 mixed with the Insomniac games is probably the best idea I can give you of what this movie is like.