Not rushed in plot, but rushed in character development. For the season finale to work, it has to be believable that Joel is really attached to Ellie, and that Ellie is okay with sacrificing herself to science. They didn’t really land that.
While you’re correct the show covered all the story beats of the game, the small talk during the gameplay is where the characters form their bond and that part wasn’t translated well. Joel still found her annoying as fuck two episodes ago, and was incapacitated for most of the previous episode. So murder spree doesn’t really hit the same.