I mean, I get why in SM we don't fight Lusamine directly with our Pokémon while she's fused because she's a real woman and: ethics. And at the end Solgaleo/Lunala are what actually attack her in a cutscene to break the fusion.

BUT this time these shitty professors were just robots. They could have made them transform into something bigger and more robotic to fight it as a boss, instead of just fighting its Pokémon team and that kills the robot somehow?? Why??