His injury list is pretty extensive, and if he's been even remotely intelligent with his money (which I imagine he has), he should easily have enough to spend the rest of his life doing whatever he wants. For someone in his position, $20 million more or so doesn't mean a whole lot, especially if you're so hobbled you can't enjoy any of it.
It’s not 20 million more or so... it’s more like half a billion if he plays to 40. Add in sponsors, commercials, and all that other extra stuff and it is even more. That is a lot of money... if he moves on to something else then good for him, but I still think he will be back. We will see.
There's no way he's playing until he's 40 with his list of injuries. Torn cartilage in ribs, partially torn abdomen, lacerated kidney, torn labrum, calf ankle of some sort, and at least one concussion. The guy's already missed 26 games in his career. Guys like Tom Brady and Drew Brees who have stayed relatively healthy could aim for something like that, but Luck would never make it that long, at least not without the quality of his play dropping sharply and turning into an even more zombiefied version of 2015 Peyton Manning.