Mewtwo himself IS the awesome for this movie. Everything he does is awesome. I don't care what the "OFFICAL" rulebooks say. Mewtwo is the most powerful AND most awesome pokemon ever!
At the end, he unleashes a huge wave of psychic energy that crashes Giovanni's helicopter, teleports an entire lake and its surrounding ecosystem UNDERGROUND, inhabitants included, simultaneously wipes Team Rocket's memories of the entire experience, and presumably destroys whatever records Team Rocket had generated since last finding him. This is after having been brought back from the dead when thrown into a Healing Spring.
And guess who gets yet another one risking his life to destroy the machines holding him prisoner? You got it, Mewtwo.
Afterwards, Meowth of all Pokémon gets one by making a speech to Mewtwo on why he should NOT erase everyone's memories again, because the cloned Pokémon have as much right to remember their pasts and heritages as any other Pokémon. Doubles as a Crowning Moment of Heartwarming.
Brock's absolutely brilliant tactical move where he saves his own life and probably the lives of his friends with nothing except a well-placed frying pan. Seen here.
...I don't get it...
OP is making a joke. If you want a legit reason, then here: Brock is the group chef, if he gets too sick to cook, the entire party, all 22 of them (3 trainers, 6 Party Pokemon per trainer, and Togepi), would starve to death.
Bug Pokémon everywhere got theirs in when, after our heroes have been captured along with all the other clone Pokémon by Team Rocket, the local Bug Pokémon show up and take down an entire Team Rocket Base. That's right, Bug Pokémon got a CMOA.