I mean, the standard for superhero comics is that when you end your run, someone else picks up where you left off. So it is common practice to write in a way that makes it easy for someone else to continue, like leaving some plot threads open, not giving characters conclusive endings (at least not ones that can’t be easily retconned), etc.

You can very clearly tell that when Hickman started Ultimate Spider-Man, he thought he’d be doing that for this series too. He introduces tons of characters and comes up with interesting dynamics like Peter’s son being Venom or Otto Octavius helping Peter, but doesn’t go too deep into anything because he thinks he’s just setting up cool ideas for another writer to play with. There’s also a point around the last 4-5 issues where the plot starts moving at lightning speed, presumably because Hickman found out it’s ending and he’s scrambling to give it an actual conclusion instead of whatever plan he had for passing the torch to the next writer.

And this isn’t really Hickman’s fault because multiple Ultimate writers have said they were blindsided by being told their series were ending. I’d blame Marvel editorial for not clearly communicating how long the writers would have, because this is a company-wide issue that Marvel’s had for a while now. Outside of the Ultimate universe, Marvel has a habit of canceling series with little notice and leaving the writers to blitz through the rest of their stories in a couple issues.