Joanne targets Louis for revenge due to a deeply personal motive. Her intention is not driven by money, but rather by a desire for retribution for her late mother, Sadie. Sadie's life was ruined by Gloria 30 years earlier (source: Vulture).
In terms of methods, specific details on how Joanne executes her revenge are not comprehensively documented in the search results. However, it is clear that her actions are calculated and motivated by a personal vendetta.
If you need more detailed information on the specific methods Joanne uses, further exploration into detailed analyses or recaps of the related content may be required.