I watched Saltburn today. I hated it

I gave the movie 2.5 stars because act 3 is the dumbest thing I've ever seen in my entire life.

I can't articulate why without sounding pompous and opinionated (and also because I lack the knowledge to explain what made it so bad).

And by that I mean, I don't understand psychology well enough to support my argument. I'll just list my thoughts here in the hopes that someone can untangle them for me. Thanks

1. Oliver doesn't come across as the sort of guy who loves prestige or power so his motive for killing The Cattons makes no sense. He seems Pearl-like (minus the angry outbursts). He also reminds me of Nina from Black Swan and Mr. Reed from Heretic... Unstable for sure, but predictable to a certain extent.

2. He couldn't have planned to take over Saltburn from the beginning. It's obvious that he develops an obsession with Felix from the beginning, not Felix's wealth, Felix.

I think he wanted to both HAVE/BE Felix... just as Tom Ripley wanted to HAVE/BE Dickie. He would have killed Felix in the end though because his psychopathy would not have allowed him to view Felix as a separate human being (I'm rambling here so if you know anything about this, please correct me)

Idk, I want to say more but I don't know what I'm getting at. All I know is his character stopped making sense the moment he slurped Felix's cum through the bath drain.