He used to score around 50 points each season. But injuries have been a problem. He missed many games over the last three seasons, including most of the 2021-22 season because of a neck injury. In total, he played just 149 games and scored 70 points with the Blackhawks.
He never played more than 16 minutes in a game.
The Blackhawks have a young team. They're likely to keep building around Connor Bedard. With Johnson's injuries and low scores, it makes sense why he might want to finish his career somewhere else.