Greta is simply a tool of her very political parents. I myself find her quite objectionable but pity her. She is being used by her parents. Her knowledge of science is minimal.
I believe it’s true that her parents are using her to gain wealth. But she has bought all this so hook, line and sinker and is so OBNOXIOUSLY abhorrent it isn’t funny. Now, she’s nothing but an insane little climate monster.