Most of what works in the Star Trek movies evolve from what we know about the characters. Kirk’s love for his ship and history with the Klingons, Picard’s history with the Borg, Data’s struggle with emotions, that sort of thing.
What character threads from any of the series could have been picked up and expanded on in movies?
I always shipped Lwaxana Troi and Odo after the episode The Muse and there was often a theme of Odo exploring his emotional side.
Some kind of sitcom with Lwaxana and Odo raising a child together would be a trip. Or a series with them travelling on ambassadorial duties, Odo providing security and the kid running around being a telepathic nightmare. Good times.