The MCU's Spider-Man does whatever a spider can and a hell of a lot besides. When Spider-Man: Homecoming literally took Peter Parker's training wheels off and the teenage Avenger-wannabe was able to explore the full spectrum of augmentations Tony Stark had added to his new Spider-Man suit. There was a parachute, different web settings and Spider-drones to name but a few, but the most intriguing was thrown in for a gag moment.
The problem is, it also created questions for the future of Spider-Man's involvement in the MCU.
The feature in question here is Spider-Man's "Instant Kill" function, which turned his Spidey suit into a more evil looking incarnation and seemed to have fairly dark connotations. After all, while he put limitations on the suit, Tony Stark surely wouldn't give a naive teenager the power to kill instantly. He's a bit of a wildcard, but he's not a MONSTER...
Even more interestingly, the idea of an Instant Kill Mode would surely be incredibly valuable to Spider-Man should he be thrust into a deadly battle with a Titanic villain with an army of savage alien invaders intent on wiping out half of existence... Like, that's the ONLY time that sort of feature would be appropriate for a kid.
So, it's somewhat surprising that Peter Parker will actually leave that suit behind when he comes to fight Thanos in favour of the Iron Spider with its added arms, which are all well and good, but not as good as something that could INSTANTLY KILL enemies. Unless that feature comes fitted as standard on the Stark Spider-Man range.
Anyway, Tom Holland seems to have a theory on why the Instant Kill Mode isn't that big a deal. In his world, it's just a matter of interpretation. He spoke to HeyUGuys to confirm that the mode actually has a much less useful purpose:
"I don't actually think the "Instant Kill" function does what everyone thinks it does. I think it simply just shuts off electricity. I actually don't think it's a killing-like piece of tech. I don't think it is to murder people. I don't think Tony Stark's that dark... I don't know if "Instant Kill" would work against Thanos."
That was directly in response to the question of Spidey using the function on Thanos, so it's somewhat inevitable that he'd be primed with a plothole protecting response. And it does make a lot more sense, even if it's a little self-serving.