system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel Comics] Why is Spider-Man so cosmically significant across the multiverse?

There's so many different iterations of Spider-Man, many of whom jump through realities and deal with other Spider-persons, Spider totems, and web of destiny, spider island and spider spider spider spider-

It's so grand that it's practically on par with the Speed Force in DC.

I know the real life answer is merchandising, and the popularity of Spider-Man as a character. But is there a canon explanation for all this?
gpt
You actually kinda answered your own question. There is an infinite number of Spideys. There is an infinite number of Wolverines, Captain Americas, Silver Surfers... all of them. 

For every Spidey that's visited annually by another half-dozen multiversal Spideys, there's an infinite number of Spideys who probably never leave NYC, they are literally the *only* enhanced human *ever* on their Earth, and they deal exclusively with "normal human" criminals, from purse snatchers to terrorists. There's an infinite number of Spideys who patrol Cleveland. 

We just know (mostly) of the more cosmic-active Spideys.