Funny enough, in Life Story, having just reread the expanded TPB with the inclusion of the Annual focusing on J. Jonah Jameson, it was actually Peter's children Claire and Benjy that beat (and killed) Morlun.
I think what makes him special is similar to the thing that makes Batman probably the strongest franchise in DC:
- He has the highest accumulation of great stories;
- He has the highest accumulation of great stories that connect directly to each other.
That last part is probably why no one seriously thinks 616 Peter’s a 20-something anymore, unless they’re carrying (unnecessary) water for current editorial; everyone tends to have just a few too many stories clearly tied together and roughly aligned to each other in a serious case of time progressing onwards.
Everyone, including staunch OMD supporters who claim that growth and change is bad, wants some piece of Spidey In High School to Spidey In College to Spidey The Night Gwen Stacy Died to Spidey Post-College Vs Harry to Spidey Vs Hobgoblin(s) to Spidey Vs Venom to Spidey Teamed With Venom to Spidey Oh No Norman’s Back to Spidey The Veteran Hero With A Spidey Family… etc., that they want to see current 616 stories be sequels to.
People will debate what specific aspects of multiple eras are “can’t miss,” and yeah, there appears to be a minority of fans and a stubborn majority of active creators who would vociferously fight against the larger fanbase and public perception that “Spidey Marries MJ” is a major component of that as well, but we *all* have too many connected stories we like for anyone to seriously demand that we just go right back to “High School Peter” and stay there… even though “High School Peter” is likely the most prevalently adapted version right now.
You could even argue that managing to get past the high school years is the most frequent sign that an adaptation is successful, so engrained is the desire to chain together multiple stories and “grow” Peter.
The argument stingy creators usually have is about how much further you should or could go; and again, I’d note that the guys behind OMD both then and now still clearly set their standard as “…a decent time after college” even at the most paranoid about change.
And since no other adaptation or AU has managed to quite string together so many solid stories and eras everyone wants, if remains the ace up the sleeve of 616 Spidey, which is again comparable to how most people treat comic Batman and his family.
I think the most stories thing is a factor. He has had thousands of adventures as Spider-Man, much more than the movie Spider-Men, who seem to have a big adventure every year at most.
Other Spider-Men are younger or have taken a few years off.