I want to tell my wife that she should find a more productive and less wasteful hobby
Why are you concerned about your wife's hobbies?
She spends money on useless stuff
You are being too judgmental and controlling. You should let your wife choose her own hobbies without your criticism.
I don't like any of her hobbies.
They are HER hobbies, not yours. Let her be and let her chose to do what she wants to do on her own. If you love her, you should support her.