Spider-Man: No Way Home (Now all webbed up with SPOILERS)

Considering his motivation... what Strange did for Spidey and the ensuing chaos would athema to him, if he is somehow aware.
I know that we wouldn't have a movie if he did this but why didn't Strange just shut the spell down and start over with the changes Peter wants? So the movie's events are really his fault for knowing better and seemingly not caring because he thought he was good enough to do it anyway.