I liked the concept of Diana and Kal together when it was first announced because I thought it would make for some interesting storytelling (not that they necessary ultimately go together long term IMO.)
It started strong, but I don't think DC "went there" enough during the duration of their relationship in how this pairing would fundamentally change the DCU - sociologically, celebrity culture, politics, hero culture, villain relationships/teaming together that might not have happened otherwise. Lots of potential, but not a lot of payoff.
Regardless it was a fun ride for what it was.
One opportunity I think they missed was having Lois Lane and Steve Trevor meet up and date during this time period. Fearless reporter meets ARGUS leader could have been an interesting story to tell in parallel to Superman and Wonder Woman.