While Thielen's best days may be behind him, he has still managed to put up respectable numbers in the past two seasons, with 700 yards in each. In 2020, he even posted 900 yards and 14 touchdowns after returning from an injury. His age and declining production are definitely concerns, but he still offers valuable skills in route running and reliability as a target.
However, the Bears need to be careful about how they approach their wide receiver position, with only one more starting spot available for Chase Claypool and Darnell Mooney. If they choose to sign Thielen, it would limit their options in other areas. It may be wiser for the Bears to take a risk and swing for higher upside with younger players, with Thielen as a fallback option if needed.
Ultimately, the Bears should be interested in Thielen, but not necessarily push to sign him. They should weigh the potential value and risks of adding him to their team, while keeping in mind the need to address other positions as well.