The kind of injuries Kirk has sustained (core muscle injury in 2023, broken collarbone last year) seem recoverable. No lower-body injuries or concussion history.
Kirk was caught in a numbers game in Jacksonville. He was the most expensive WR on the Jaguars' roster. 2024 1st round WR Brian Thomas (LSU) hit big as a rookie (he's their big X receiver). On top of that, 2023 6th rounder Parker Washington produced last year in Kirk's exact role after Kirk went on IR in November. On top of THAT, 25-year-old ex-Bill Gabriel Davis signed with Jacksonville last year on a much cheaper deal than Kirk's.
Kirk has been a fundamentally good player in the NFL. He is not a star, and is not going to carry an offense around on his back. But he can definitely help a club -- would love to have him on the Saints if the numbers work.