Were dinosaurs already dying out?

Could you elaborate on the statement, "Were dinosaurs already dying out?" Are we discussing a specific time period within the dinosaur era, or are we referring to the broader question of whether dinosaurs were already on a path towards extinction before the catastrophic event that ultimately led to their demise? Are there any scientific theories or evidence that support the idea that dinosaurs were in decline before the final blow? And what impact would this have on our understanding of their extinction and the history of life on Earth?