There are obviously certain examples where story elements carry over from one episode to the next, such as Maude Flanders and Mrs. Krabappel’s deaths, but most of the details aren’t meant to be seen as permanent.
If they were, Homer and Marge would be in their 70s and the kids would all be full-grown adults and living their own lives.
Yes, obviously, but it’s not going to happen.
Do I wish that there was a spinoff of Ralph Wiggum in his 30s?