If this is his last regular season game, the duo of Brees/Payton averaged 28.3 points per game

100%, 2012... removing that season gives you 212 games together (excluding playoffs). I must have erased that season from my memory.

However, I am getting 6280 points-for for 2006-2020, minus 2012 (https://www.pro-football-reference.com/teams/nor). But I bet those stats include playoff points.
You can't just count them all like that, he missed the last game of 2009, 2018, a game in 2015 after he dinged his shoulder in the game vs Tampa. Then the 9 games he missed these past 2 seasons.

Trust me, I was meticulous in my data gathering.

Adding in the playoff games

6450 points
228 games

28.3 average