In novels, the Prince of Demons usually did not directly PK the Princess because the Princess was usually a character in a novel or anime that represented a specific country or power, while the Prince of Demons was another character that represented a different power or goal.
In some novels or anime, there might be a battle between a demon prince and a princess, but it was usually because of a conflict of interest or goals between the two parties, not because the princess herself had evil characteristics. Therefore, the plot of the Demon Prince vs. Princess might appear in specific novels or anime.
Sure is! Frieren has a dedicated fan base thanks to its engaging plot and well-developed characters. The manga has attracted a lot of attention in the comic world.