Playstation was around before Xbox. Playstation1 was released in 1994/95, whereas Xbox Original was released in 2001/02.
Plus the PlayStation 5 has sold 18.87 million units in 17 months, while the Xbox Series X|S sold 13.87 million units at around the same time.
The fact of the matter is that PS4 games generally output at higher resolutions than their Xbox One counterparts.
Therefore the majority prefer the Playstation because it is the original console out of the two, has a higher popularity rate, and has better resolution.