As for his ability on the field, he’s as confident as ever. In a comment that could be seen as either harmless hyperbole or incredible overconfidence, he said that there’s no real competition at the position, in his mind.
“I don’t feel like I have to come out here and show anybody anything or why I’m better than this guy or better than that guy. It’s more about going out and affirming that for me, I go out and I play, I know I’m the best quarterback on this team. I feel like I’m the best quarterback in the league and I have to go out and show that,” he said. “Any athlete at any level, if they concede to someone else, they’re not a top competitor, they’re not trying to be the best that they can be. There’s guys in this league that have done way more than me. But, I still view myself as the best because that’s what I work toward every single day.”
https://www.washingtonpost.com/news/dc-sports-bog/wp/2015/08/17/rgiii-i-feel-like-im-the-best-quarterback-in-the-nfl/?tid=pm_sports_pop_b
And this is why he'll never live up to his potential - he thinks he's already there, so why bother listening to anyone who's trying to help him get better?
All I know is Cousins needs to get another shot this season. Maybe he won't do anything with it, but at some point he needs to get another shot IMO