Some bosses aren't just easier to beat if the player has learned all the game's mechanics, they require it. They have moves that echo every foe in the game or have defenses that need every tool the player has to beat them. In some games, the player has to know what they're doing at all times to defeat the bosses.
The Blight Ganons are four of the most significant bosses in The Legend of Zelda: Breath of the Wild, each a limited aspect of Calamity Ganon. Each has their own mechanics and their own strengths and weaknesses that the player can use to defeat them.
Calamity Ganon is the game's final boss. In his fight, he uses each Blight Ganon's mechanics and shares their weaknesses. Breath of the Wild pits the player against any surviving Blight Ganons before they can even challenge Calamity Ganon. To make sure they know the mechanics, the famously open-ended Breath of the Wild forces players into specific fights to proceed.