Richardson is only 23 years old (24 next month). So while like most players, his ambition is to be a starter and make starter money, he has time to do so. As I mentioned, the smart career move for him would be to get the Colts to trade him to a team where he isn't stuck behind 2 other QB's on the depth chart. That way he can at least compete for the starting position in camp and if nothing else, like Malik did, learn his craft as the #2. I just don't think there are any teams who are willing to give up much, if anything for him, as well as pick up his $10M+ 1 year contract.
Prior to today, I assumed Richardson was the Colts #2 QB behind Jones, but that isn't the case. The Colts have Riley Leonard as their #2, so not trading Richardson might cost them a roster spot. So while the Colts won't save any cap by releasing Richardson, they would pick up that roster spot. Also, if Richardson has become a disgruntled and not a good player to have on the team, even more reason to just say "F the late round pick, lets release him."
If the Packers would pick him up off of waivers, and figure out a reasonable 2 year deal ($3-4M/year), he might be worth the gamble. However, if they value Ridder equally or higher than Richardson, they don't even have Anthony on their radar. Personally, I think Richardson is the better player, with the higher upside.