As people have said Indy isn't totally screwed. I mean, it sucks ass to lose your cornerstone QB, but Indy is in a select bunch where their backup QB gives them a shot to stay afloat.
In the year Luck was shut down for his shoulder, Jacoby Brissett was called on to essentially carry the load for the entire season in his second season in the NFL. His stat line actually wasn't half bad given how awful the Colts roster was and the circumstance:
2017 Brissett; 276/489 (58.8% completion rate), 3089 yards, 13 TD/7 INT, 6.6 YPA. Tack on 260 yards rushing too
Promising numbers for a guy essentially thrown into the fire. Given the Colts roster is way better now, this guy might surprise people.
Luck chose his health over the game, and i don't blame him. He made millions, has a stupidly valuable degree in architecture from Stanford. I honestly think you won't ever see him come back.