i had a player, calvin flannigan, that was recruiting to be a career backup. after a redshirt year, he was a huge contributor his last 3 years, leading the team in scoring the last 2 i believe. he was 2nd all time in school scoring, and helped lead the team to 3 straight national championships. he was a d2 sg with like 93 speed and 97 per or something, in the old engine, but his def and pass were low enough that i didn't want to start him. his collegiate stat line reads, a whopping 139 games played (140 is the max possible), 0 games started, 18.4 minutes, 48.4% fg, 44% 3pt, 1.1 stl, 1.0 assists, and 10.9 points (all my teams then had extremely balanced scoring, so that was a super high figure, for someone to average over 4 years. i think he capped around 13.5 and was up to 9 or so by soph year).
i have had success, obviously not the same level, but still a lot of success with a career backup, particularly at the 2. you can just get such efficient production from an offensive star who might not quite have the def, passing, or something else you would want on the starting line.