Brown is a better shooter, scorer, mentally tougher, clutch, is effective in different lineups and matchups (doesn’t need to be surrounded by 4 shooters to be at his best), just as versatile defensively, and most importantly, has improved every season, while Simmons has plateaued.
Simmons plateau is high, I like him as a player and think he will rebound and eventually thrive in the right situation (a team willing to bend over backwards for him), but Jaylen’s improvement has raised his value as an asset to be on par or above him.
Jaylen, at 25, is already one of the best scorers in the NBA, what happens in 2 seasons when he learns to control the game by getting to his spots on demand, commanding the double, and either shooting a high efficiency shot or hitting the open man? Does he become another version of Kawhi?