Personally, I liked the Eternals, both the movie and the characters. I appreciated than none of them wanted to be superheroes or to go around saving the world. They had spent thousands of years fighting Deviants, believed that they had killed all of them and were taking a well earned retirement. Having nothing left to prove is something that I can relate to. So they acted, did teaching, raised a family, started cults; you know, normal stuff. Personally, I found them much more relatable than Tony Stark, Peter Parker, or Thor. I was rooting for them, and consequently found the ending poignant.
Obviously, many other people found them otherwise. Well, you all do you.