The game proves your point. The knights were very active and the bishops were ineffective. The knights also could protect themselves (28 Ngf7+) while bishops can't.
It is true the knights can be more active on certain boards. But isn't it true that a king and two nights cannot mate a lone king? Two bishops and a king can force mate a lone king pretty simple. That is the explanation my mentor gave me why bishops is generally considered stronger than knights. Only the board and there activity determines if I want to exchange them tho.
Usually, bishops are considered slightly stronger than knights. Many players, myself included, are often hassitant to trade their bishop for a knight. However, in a closed game knights can become very powerful. In the game below, played live here on chess.com, I trade both of my bishops for my opponent's knights and manage to keep the board closed. Even though my opponent gets a seemingly strong outpost for his dark square bishop, it proves useless as my knights wreak havoc. Although mistakes were made on both sides, I think this is a good example of how knights can be stronger than bishops. Comments and critizism welcome!