Efforts to spin out mutant characters from the X-Men universe weren’t necessarily successful, until both Logan and Deadpool proved that you could — and should — take different avenues with superhero genre movies and find an audience… so long as it speaks to the fans of the characters.
Channing Tatum brings up an excellent point.
Had the Gambit movie been rushed into production several years ago, when the movie was trading directors and zipping through screenplay drafts, then it would have been caught in the weird X-limbo that could have put it more in line with failed X-Men spinoffs, like The Wolverine.