So, what happens on a show called Prison Break once the characters get out of prison? The long answer is complicated, but a short answer is "nothing nearly as exciting as when they were in prison."
Though the second season had some things going for it, there's a reason that the characters got sent back to prison at the end of season 2, only to attempt an escape once again during the following season. It's difficult to sustain a show once you remove the original premise. Many showrunners have attempted to keep a show going past it's logical conclusion, so you can't help but give the Prison Break team some credit for taking as daring a risk as taking the show beyond prison walls, even if it didn't work flawlessly.