3. Strength
Spider-Man can generally lift around 15 tonnes (as a general rule). I'll just specify that again: Peter Parker can lift 15 tonnes under his own power. That's him holding a building up in the picture - a feat a little bit above his standard showings, but a good depiction of the fact that he is
considerably stronger than Batman. One landed punch from the webbed wonder and Mr. Wayne would be out for the count - and that's if he was holding back (as he tends to do). If Spider-Man was bloodlusted and he punched Batman, Batman's face would explode. Spider-Man has actually been shown on panel lifting a tank with maximum effort, which is probably just bad writing given that those things weigh between 50 and 70 tonnes, but he regularly lifts cars and has lifted a train carriage and his punches have hurt villains with considerably more durability than Batman, so his strength is an enormous threat to the caped crusader - in fact it's simply out of Batman's pay-grade.