As noted in the previous message on Colossians 4, the list of greetings to teammates is not simply a vestigial element just for the original audience. Paul knew when he wrote that list that his letter would be passed around to multiple churches in multiple cities.
Paul—and ultimately God—wanted us to see something important here. We are meant to recognize the value of faithful teammates in the work of the gospel. We are meant to understand that every believer has a role to fulfill and must remain faithful in that calling. And we are meant to be encouraged to persevere in our mission, guarding against complacency, laziness, and worldliness, while being reminded that every member of God’s family matters deeply in the work of His kingdom.