With the new feature introduced for bosses, they were allowed to switch pokemon. In this case, attacking with stat-destroying moves in hard level boss battles was useless.
+400 e.v. It's impossible to control a Pokemon with stats without a stat reducer. The carrier is also useless as there is not enough environment for the buffer pokemon.
It's not impossible to win boss battles without the old system, but it's very difficult. Double bosses are IMPOSSIBLE.
Fix boss update please...