While I liked the film and felt it fairly damning of Carter, the Carter voiceover at the end, by implication, gives him some credit. This voiceover was gratuitous, and indicative of Affleck’s intention to end the film giving vague kudos to the peanut farmer.
Kind of like when Oliver Stone ended his Nixon movie, by showing Clinton saying glowing words about him at his funeral.
The only thing they gave him credit for was negotiating until the end of his presidency. They studiously avoided saying his negotiations accomplished nothing. That’s the hard part about the Carter presidency for a lib, it’s hard to give him credit for anything since he never came close to accomplishing anything.