The first part of your first sentence is correct. I rather think that that moment would have been different if the cast was older, if only ever so slightly different. I don't want it to stay that way for myself. I just think a highschooler in 5 years should be able to get into P6 on the same level than a highschooler back then getting into P4. And I think the cast being the same age and the setting being a similar one to your real life situation, helps. Helps, mind you. It's obviously not necessary by any means, or the main reason why these games resonate with people. But it's still part of it, imo.What I have gathered from all of your comments here is that the series really resonated with you at a particular moment in your life, and part of you feels that it should always stay that way because of it. You say its so future generations also won't "miss out" on the same experience, but I think its really about you not wanting your perspective on it to change. Personally, I am all for new experiences that constantly change my perspectives. At worst, the games you loved will never change.
Maybe I'm wrongly assuming it was like this for most others playing it back then. I only spoke with a few people about this (because well, the games weren't that popular baclk then) and most of them shared the same feeling.