Most downloaded on PS5. Not surprising considering it was the top physical PS5 game by a wide margin.
It's possible FF16 didn't beat Monster Hunter World's PS4+PS5 2023 digital numbers considering it had only a fraction of the physical sales, and MHW has had a good long tail (FF16's long tail is concerningly bad).
Too bad we don't have numbers; it's not even clear if FF16 topped 1 million in Japan, which would be nuts for a mainline FF.