And then afterwards, they started integrating some of the characters into other books. Gilgamesh/The Forgotten One joined the Avengers, then he left and Sersi joined, Makkari started hanging out with Quasar, the Deviants (or at least Ghaur) became major villains in the Atlantis Attacks storyline, etc.
The Eternals were basically one in a long line of titles that Jack Kirby kept making because he had big ideas but seemingly never managed to successfully get them across. It started with a lot of the Tales of Asgard stories in Thor, then when he left Marvel he basically went and did a newer version of the same ideas with the New Gods at DC (which is where Darkseid and Apokolips came from), and then he got pissed at DC and went back to Marvel and basically did the same sort of idea again as The Eternals.
Marvel mostly adopted the core ideas of the series and integrated them into the entire universe as an excuse to explain away bad science. Why do so many Marvel heroes get super powers from radiation instead of just contracting cancer the way people do in the real world? Yeah, umm, the Celestials experiments on humans a million years ago, and the extra genes they added cause super powers. It's also why mutants are a thing. Problem solved!
The actual Eternals themselves haven't been around for years, though, because they're kind of lame.
They actually had to hand out pamphlets in movie theaters explaining some of the concepts, so you could keep track of stuff while you watched.
If a movie gives you homework, something has gone wrong somewhere.
For the same reason why 51% is a failing grade in every reputable school.
You are misreading rotten tomatoes kid. With a test it is an aggregate of correct answers.
Rotten tomatoes people could all give something a 6/10 but it could have a percent on rotten tomatoes because it just measures if someone liked something not how much. I dont really trust rotten tomatoes as much as IMDb for this reason.