The world of the story is not the real world.
Readers are able to keep two ideas (and many more) in their head. We understand fiction is an allegory for real world but is a mirror. Fiction has versimilutude but it’s not objective reality, can never be objective reality.
We are able to understand that Peter referring to John Belushi on SNL does not actually mean that adventure took place fifty years ago in Peter’s life and Peter is now fifty years older than he was then. Because real time and Marvel time have never actually lined up. Marvel is its own world, with its own rules.
The reason why Peter should be allowed to grow is because that’s what humans do.
We learn from our experiences (and if we don’t learn, that is a tragedy and another type of story to explore).
We are motivated, inspired, switch our positions, change our minds, create new goals in response to our experiences and how we act and are acted upon by the world.
If Peter Parker is to be a fully dimensional and relatable human character, then he MUST learn and grow. And that’s what he did, until 2007.
This doesn’t mean that big, sweeping changes are made at the end of every story or a major character dies at the end of every arc or Peter gets married one year, divorced the next, remarried the following year.
What it does mean is that Peter’s experiences
matter and his reactions are
motivated and
consistent. If he learns that the symbiote is susceptible to sound in one issue, he uses that knowledge the next time he sees the symbiote.
This isn’t Spider-Man, but let’s look at Jackpot. Mary Jane encountered Francine Frye in ASM 25 by Spencer. She uses her acting skills to disarm Francine.
But in Jackpot #1, MJ acts as if she has never encountered Francine before, and then she overacts and can’t fool Francine - and it’s not explained why MJ suddenly can’t fool Francine and why she’s suddenly a terrible actress.
That’s treating MJ as an inanimate action figure, not a character. And it happens to Peter over and over and over again as well.
We want Peter’s experiences to matter.