Comedy about Relationship Sabotage

I’m trying to recall the title of a comedy in which a woman is disappointed with her life and jealous of her friend’s relationship. She goes out of her way to sabotage it, and ends up failing each time. An eccentric dimwitted acquaintance of hers occasionally and eagerly volunteers her own ludicrous schemes to help, and those have devastating/amusing consequences for the protagonist, and her life is immeasurably worse.

Ultimately, in the final act, she ends up alone with no where to go, and she visits her eccentric acquaintance’s apartment to talk and she offers the protagonist her couch to sleep on for a few nights. The protagonist politely declines seeing how small and disheveled the space is. The acquaintance responds that’s it’s perfectly okay–she’s actually incredibly wealthy and owns the entire floor. She says that it’s so large she wouldn’t even see her and that she hasn’t even been in all the rooms yet and (jokingly?) says she uses an ATV to get from one hallway to the next.

COMMENTS: It’s the final dialogue that i remember most vividly (in addition to the film’s overall theme).
I thought the eccentric character was played by Rebel Wilson for some reason, but I haven’t seen most of her movies, except for Bridesmaids–which fits thematically. But I seem to recall Wilson only performing briefly in the first act…and the protagonist having a much happier ending, so I don’t think it was that film.