It wasn't skill that Miles gained, it was confidence.
Doesn't Spider-Man solely fight using his spidey sense and acrobatic skill? Add to that invisibility and shocking, then Miles would be pretty good for a rookie.
Well whatever you wanna call it, I felt like that jump was too quick. It should've built way more gradually.
I've thought about this recently. I think Peter Parker specifically is as good as he is because he's a genius. He has the crazy athleticism in a way that he interprets combat best. Hence making his own web shooters too. That's the cool thing about Spiderman fighting, he's really resourceful and understands his own movement well.