This is what I think: I think characters need to be genuinely challenged in order to have good storylines. Iconic storylines are the ones that put the character through the wringer, physically and mentally.
Kamala's never faced any real challenges, and she certainly doesn't have an iconic villain like the Green Goblin, the Joker, Bushman, Zoom and so on. You really need that one guy who could actually destroy the hero's life, in addition to all the mooks.
I don't think you can have a ongoing comic book series where the protagonist isn't constantly challenged. I mean, a typical manga is all about an escalating series of challenges, one after another, with the occasional confrontation with the personal rival or the really deadly villain. Compared to what, say, Peter went through, Miles is on fairly easy street.