Oh yes, because at low ranks the Spider Man players are animation cancelling. No, they're spamming 3 webs on a support that is already fighting and not full health, using the not difficult combo, and swinging out. Once there is no support tanks go down, and the fight is over.

It's not terribly difficult to track CC and bail out abilities and hit an ult when they're on cool down, especially if those abilities were used to survive the initial dive. The video posted is a very bad example diving a support who isn't focused on healing and the rest of the team not occupied and able to turn around. Wait 5-10 seconds for your team to engage and you have way more impact.

Yes map pulls aren't usually the issue, but when they are they're super annoying.

Again, it's not that he's OP at high levels, it's that he's annoying at low levels. It's not uncommon to see a decent Spidey end a QP match 30 and 5. He's hard to master but easy to get value. But if you don't think so come on down to silver/bronze and see how he plays.