>>542374165
Carries rely on item/farm more than any other character.
If a carry is behind on souls, they're effectively worthless as their kit doesn't give them a huge advantage inherently. It's only when they're matched or ahead that they're able to dish out good damage. Carries have to constantly make sure their macro is good to have the most effective soul lead they can get.
Compare that to almost every other character who have multiple ways to affect a fight even if they're behind. Someone like Lash definitely needs items for his damage to be meaningful but at the same time, he doesn't need to be the main damage dealer. His ult is a huge threat to clumped up enemies and his slam can knock enemies out of the air or knock them up so they can't get away as easily. Someone like viscous has his extremely good cube, his punch can disrupt enemies a lot, and his cube can be a big annoyance while giving him a ton of defense.
The only characters I can think of off the top of my head that aren't gun carries but still rely heavily on items are victor, yamato, and shiv. If they're behind they become really easy to destroy since they have no CC but they're also characters that can sometimes work with gun builds