It's true that no single stat in a box score captures the true value of what a player is doing right or wrong when they are in the game. Over time, however, the plus/minus ranking has value worth giving weight to. While it might not fully credit individual great plays like Haliburton delivers, it does tend to flag a pattern of mistakes that lead to defensive breakdowns that make it hard to get stops. You don't win games by contributing 10 points if you have defensive mistakes that allow 15 easy points for the opponent.These raw plus/minuses are absolutely awful metrics, they don't take into account what the player did on the court at all. Haliburton had a triple-double but since he played every minute of the game his +/- was guaranteed to be the final score differential, -2. That is in no way representative of the kind of game he had. Similarly, Conditt's was -4. Jacobson had the best with +6...if only everyone else matched his numbers...??
The best player evaluation system needs to be much more extensive than any single stat. LE would breakdown and quantify almost every action that a player would take or fail to take during the game. The typical player would be graded on over 200 evaluation points in a game.