She didn't have any clear growth in the trilogy: she begins as a talented reporter and ends up as a talented reporter, who learnt about aliens and got engaged but we didn't see how it affect her, how it changed her as person.
The whole arc for Lois has been about how the alien, Superman, changed her. Lois starts out as an ambitious reporter who will defy Perry White -- even face legal action -- to publish her alien savior story. But she changes when she meets Clark Kent. She decides not to print her follow up story, which is so out of character for Lois that Perry remarks on it. Lois goes from cynic to believer. From someone who can't wait to publish secrets to someone who will keep the biggest secret to protect what she believes in so dearly.
BvS builds on that arc. For Lois, BvS is about how she deals with her own powerlessness. Bruce, Lex, Clark, Keefe, and humanity as a whole are wrestling with existential questions. Lois is, too. What happened in Nairomi gives Lois nightmares and keeps her up at night not only because she no longer is certain that she should be an important part of Superman's life, but also because the warlord's words ring true: Ignorance is not innocence. Lois, therefore, has to find a way to past her existential crisis by using the pursuit of knowledge and truth to validate her passion (Superman) and her profession (journalism). Ultimately, by getting to the truth, Lois finds her way back to belief.
The death of Superman is a major blow for Lois in JL. I'm not fully on board with Whedon's changes, so it's difficult to track Lois's arc after BvS. But the throughline seems to be about Lois finding inspiration again. It's about her holding onto hope.
We never knew why she wanted to become a journalist, what her motivations were, who her family was, what's her story besides her being a journalist. Which made it hard to emotionally connect with her.
I'd love some more Lois backstory, but it's not necessarily out of the ordinary for cinematic Lois Lanes to be opaque. I think the only thing we know about Kidder's Lois is that she has a sister who lives the kind of ordinary life that Lois eschews. From what Adams's Lois says when she arrives in Ellesmere, journalism is her jam because she is addicted to adventure. She gets writer's block if she isn't wearing a flak jacket. If I compare Lois with Black Panther's Nakia, for example, I don't know much about her family, her background, or her reasons for supporting Wakandan outreach efforts in Africa and for the African diaspora. I didn't find it difficult to emotionally connect with either character.
In a lot of comics, she makes mistakes, can be sometimes mean/haughty, is not very organized etc. I wish we had see more of her messy, imperfect side of her (which could have given us great and funny moments). More mundane scenes with her would had been great. After 3 movies, I still don't know a lot about her.
I thought it was funny when Lois photographed the Kelex-type service robot in the scout ship. It was nice to see her at her apartment making a cup of tea before the FBI arrested her. Watching her drink scotch at the bar with Woodburn who told us Lois once called his blog "a creeping cancer of falsehoods" was pretty awesome. Lois is obviously protective of Jenny, which we can see when she warns her to just say no to Lombard's advances. The way Lois treats "Jimmy" and refers to her rapport with her usual photographer, Heron, fleshed out Lois more, in my opinion. Lois clearly seems to have a good relationship with the police. It was interesting to hear the lab tech (Jenet?) talk about Lois's idealism, even naivete, despite her reputation and career. There was also a sense of intimacy created when Lois returns to her and Clark's apartment after the incident in Nairomi. Later, we see her drinking wine and watching the news in casual clothes. Lois in Whedon's JL is very much messy and imperfect. I feel like I've seen a lot of Lois's sides, and I have a pretty good sense of who she is and how she feels. More would be great, though.
Steve was a better lead imo, because his character helped the plot moved forward but we also got to know him as a person better.
Really? I think all we really knew about him was the small cliche story about his dad and whatever insights one gets from observing his relationships with Etta and his team, which we get with Lois and her teams, so to speak, of Perry/Jenny/Steve or Hardy/Hamilton/Swanwick. And both he and Lois helped move the plot in their respective films. Lois, in my opinion, plays an even greater role in MoS and in BvS because the way she serves the plot is through her having an arc of her own that parallels the other main arcs in the film.