Drew Brees as the next head coach

Nope. He hasn't been away from the game long enough to transition to coaching. Not every player can coach. The best coaches that were players usually weren't great players.
That is true, most great players don't make it to coaching because they don't want to or have to continue working. They made enough money during their playing career they can do anything when they retire and not have to go through the grind of coaching