Benoit is the one who started the declining arm narrative back in 2015. I wouldn't necessarily care, but it's been shown to be not a big deal, Brees has said he's still close to where he's always been, and Payton says Brees is close to where he's always been.
And I despise false narratives permeating this message board and becoming "fact" when there is no legitimate sourcing for it to be accepted as such.