I am not sure I agree, since Peter Parker is no longer a high school kid with a side hustle of taking pictures for the Daily Bugles. But there's a major point to be made here...
Broadly speaking, there's a span of time a person reads comics, and, last I read, it was 2-4 years. The bulk of comics (also meaning - the bulk of DC/Marvel) readers pick them up somewhere in junior high or high school, and then stop in late high school or college, as their use of money changes. Comics can be an expensive hobby, after all.
So, while there are some diehards that will read for decades, they aren't the majority of the market. I think you'll find that the period of Marvel resets like that is... 2 to 4 years. This, as I understand it, is intentional. A typical reader will see only one or two such events for their favorite characters, and that's okay. They don't see the longer-term pattern.
I find DC heroes less relatable simply due to their sheer power. They are, by and large, gods. That's just hard to identify with.