The Fantastic Four was a single story where every event led to the next:
1961: the origin
1962: they adjust
1963: they discover ever increasing dangers
1964: Reed and Sue are engaged
1965: they marry
1966: the increasing danger climaxes with Galactus
1967: as defence from Galactus, Reed researches subspace
1968 (published 1968-70): Franklin has subspace powers
1969 (published 1970-72): it all becomes too much: health problems
1970 (published 1973-74): their marriage almost ends
1971 (published 1974-78): false dawn: apparent final defeat of Doom
1972 (published 1978-81): in denial
1973 (published 1981-87): climax: things have to change
1974 (published 1988-?): Reed and Sue retire: a new team begins
In 1988 Marvel stopped publishing this complete story. Editors panicked that Reed and Sue retired, so they brought Reed and Sue back, reversed Johnny's marriage, and ignored the character development and logic of the previous 20 years. From that point all permanent change was banned. This was part of the wider death of continuity that killed the Marvel Universe.
What was the Marvel Universe?
The Marvel Universe was not just a collection of characters (every publisher had that). The Marvel Universe was
"a series of titles where events in one book would have repercussions in another title and serialized stories would show characters' growth and change."
- Wikipedia
Before 1961 this type of universe did not exist. Superman and Batman would sometimes team up, but those events would soon be forgotten and would never change the status quo. After 1991 this type of universe did not exist: Spider-man and Wolverine would sometimes team up, but those events would soon be forgotten and would never change the status quo.
This page shows how and when the Marvel Universe died. In brief, Marvel Time destroyed the Marvel Universe by preventing permanent change.
What made Marvel comics great? What made Marvel revolutionize the world of comics in the 1960s, and create characters that are still the foundation of the company today? Stan Lee told us straight, right at the start, in Fantastic Four issue 9:
INCREDIBLE EXPLOITS and DOWN-TO-EARTH REALISM.
Remember that formula: it's all you need to know!
(And good value of course, but that should be obvious.)
Doom had two great triumphs. First the capture of the Surfer's power Cosmic, and later briefly obtaining the Beyonder's power. But in between there was a story that everyone is supposed to hate as "out of character": the apparent attempted rape of a Latverian girl. Yes it is out of character if we only look at Doom's triumphs or his self image. But if you follow Doom's career from start to finish we see a different story.