The actors who populated Phase One have had the most experience in the MCU, and that includes Bucky Barnes actor Sebastian Stan.
Bucky made his debut back in 2011’s Captain America: The First Avenger, seemingly perishing in the battle against HYDRA.
He’s since popped up a whopping four more movies, and apparently it took years before the fandom took notice of the character.
The Marvel Cinematic Universe has been going strong for a decades of filmmaking, with the OG actors in the midst of long tenures in the massive franchise.