While he did manage to find a role on the offense, in large part simply because Pittsburgh Steelers quarterback Ben Roethlisberger happened to take a liking to him both on and off the field, the reason that the team brought in Ryan Switzer via trade in late August was because they wanted to bolster their return game without relying on JuJu Smith-Schuster to do the kick returns as he entered his first season as a full-time starter.
Switzer had success both in college at North Carolina and during his rookie season with the Dallas Cowboys in 2017 as a returner, functioning both in the kick return game as well as doing punt returns.