This quite wonderful article about PEYTON PLACE is wonderful because it mentions how the show's duration and stable writing team were the show's "hidden asset": 

Duration was Peyton Place’s hidden asset. Its creators had the luxury to build characters over the course of years rather than within the confines of a fifty-minute hour. Because the writing staff was relatively stable after the first year, Peyton Place developed a terrific institutional memory. Complex characters remained emotionally consistent throughout years of labyrinthine plot twists. 

Betty Anderson, one of only three regulars who lasted for the whole five-year run, may have benefited most from the writers’ skill for deepening and reinventing their characters. They paired Betty romantically with lawyer Steven Cord (James Douglas), a fellow social striver whose illegitimacy gave him a world-class inferiority complex. (...) The writers also threw out frequent callbacks to Betty’s past with Rodney, reuniting them occasionally for what-might-have-been scenes in which they came awkwardly to terms with their failed marriage and lost child. With years of backstory to draw upon, O’Neal and Parkins could play varied notes of jealousy, ruefulness, sweetness, and mordant humor, building an emotional array that could only exist in a series with the longevity and continuity of Peyton Place.

https://www.avclub.com/why-institutional-memory-was-peyton-place-s-hidden-asse-1798241844

It got me thinking about daytime soaps and their institutional memories. I always felt Y&R lost theirs when Kay Alden was dumped in 2006 which is part of the reason the show is listless today. From what I recall of Jill Farren Phelps' Locher Room interview, she took Mary O'Leary (please correct me if this is the wrong person) from GUIDING LIGHT when she moved to ANOTHER WORLD and O'Leary was considered the walking encyclopedia of GL. Could losing their "expert" have been part of the reason GL never recovered?

Can we think of other examples where losing the person who "knew" the show either hurt it or, in the inverse, made a soap opera stronger?

Wasn't Agnes Nixon at one point barred from the writer's room?

I think the execs were more interested in what's happening at the moment than bothering if it contradicted the past.

Even shows that had a stability like Bell's Y&R and Irna at ATWT dropped characters and plots that jarred with viewers.

For years Jill acted as though she had no family of her own.

I remember Erica Slezak ad libbed a mention of Joe's family at his funeral as the writers didn't reference them, so often it is the actors who have that memory within the character.

Off topic slightly, Peyton Place being 2 aweek primetime serial had a different structure to daytime-it was much easier for them to keep a tighter rein on the format.

They didn't face actors leaving, competition from other soaps,low budgets etc. Nonetheless,PP could have played as a daily serial. There were lots of moments and plot points that were missed due to lack of time.

 

I think the nature of the genre before home recording plays a huge part in their use of history.  Bill Bell retold several stories with different characters across a couple of shows, ignored details of stories and character history when he wanted to, and dropped family ties as the characters moved on without really bringing them up again.  Because they could get away with it easier due to the nature of the shows airing once and then for many people that was it.

Sometimes I also think fans of the genre, and those of us that post here that are super fans, we expect every detail to always be there and them to mention every character all the time.  Yes the history is important, but sometimes around here it seems like we locked into minutia.  But I do think these shows should have held on to people that knew the show inside and out, and kept mentoring a new generation to do the same since they last so long.