Making Backgrounds Without AI

The old fashioned way... Actually I tried to use AI just to see if the results were better or worse. It simply could not understand that I wanted the point of view to be from standing on the pier and that I wanted the pier to be horizontal.
BTW Filmora does have AI enhanced normal operations like green screen filters. It can also generate images and videos that are complete fabrication. HOWEVER, they charge you for that. Since the AI I have used lately has required a minimum of ten generations to get what I want, that would be way too costly. I have a year subscription to Envato. I'm happy with it but it's not good for generating sound with video.