First of all their trinity,
Guess you don’t sing Askinu Sudasa by Shalus Shudis (Seudat Shelishit)?
second of all their icons and statues of saints they literally bow down to!
But they do not ascribe divinity to it/them. That is Halacha Pesuka.
The reason why it would be Avoda Zara is because they worship a human.