Warning: Justice League spoilers ahead! Read on at your own risk!
Justice League doesn't open with a big action sequence; instead, we start with a group of kids interviewing Superman on the street in the wake of a disaster. Right off the bat, it's clear that this is a different (read: much more hopeful) Superman than we have seen in the DCEU before. At one point the kids ask the last son of Krypton to name his favorite thing about Earth, and the scene cuts to black just before he can answer. So what does Supes think? Well, according to Henry Cavill, the best thing about Earth is the human capacity for love. The Superman actor said:
I think --- and I imagine Superman would also think --- the greatest quality of people and humankind is their capacity to love regardless of hardship or difficulties or personal trials. People can be living in the most horrendous war zone or under the most incredible oppression and yet they can still love so selflessly and so unconditionally --- and still bear hope through that love. It's amazing to see what people can do. I think Superman would recognize that and appreciate it.
That statement shouldn't necessarily surprise you, as it's the whole point of Superman being on Earth in the first place. In Man of Steel, Jor-El (Russell Crowe) tells Superman (Henry Cavill) that he will give the people of Earth an ideal to strive towards. Even Jonathan Kent (Kevin Costner), despite his efforts to hide Clark, knew that Superman would one day change the world. It all stems back to a nurture over nature argument in the sense that Superman has godlike powers, but the moral values instilled in him at a young age keep him grounded.
That's why some of Superman's most iconic moments in the pages of DC Comics have nothing to do with big action sequences. They're all about his ironclad will and his willingness to do anything for the little guy.
Henry Cavill's remarks to The Los Angeles Times about Superman's eternal optimism echo the nature of the character in the pages of DC Comics, but it's a nice change of pace for the silver screen version. Thus far, the DCEU has shown a much more cynical and jaded Superman through the events of Man of Steel and Batman v Superman: Dawn of Justice. However, with the release of Justice League, the character has finally come full circle and embraced the qualities that fans of the "true" Superman have come to know and love.
That said, despite the return of a more traditional Superman in Justice League, it remains to be seen whether or not we will get another solo movie for the character in the DCEU. Rumors related to Man of Steel 2 suggest that it's not a priority for DC at the moment, which seems to indicate that Henry Cavill's Clark Kent could become a supporting player for the next couple of years. Not that we're complaining, since it's just great to see a hopeful and optimistic Superman back on the big screen.