Wanted to say one more thing about the subject of him being less relatable as an adult, I disagree based on my own experience. Kid's play grownup all the time, they like to imagine themselves older and look forward to that time. I know I did and it was very natural when reading a married Peter at 12 years old to put myself in his shoes and imagine me like I was him.
It was also very healthy for me to see how he and MJ loved each other despite all the problems in their marriage. Growing up I did not have an example of love like that between my parents, and I owe it to Spider-Man that I value marriage to the extent I do today. It has helped me overcome every adversity and value and love my wife because I had Peter as an example growing up. I wouldn't trade that for the world.