The photo must be suitable for a million dollar advertising campaign and be the best possible. Arcachon has poor composition. Look in the corner. In general check the pixels are clear and sharp at 100% or 200%.
The composition of the photos isn't very good. You have the horizon cutting the photo in half.
Also, there can be problems with smartphones. They don't enlarge very well because the pixels begin to show when they are enlarged. Ok for small screens, but rather not for big screens and prints.
Have a read of this from Adobe about how to create better photos:
These are nice vacation photos for sharing with friends & family. But as Stock photos go, they are nothing special.
Adobe Stock looks for highest visual and technical quality. See links below.
Stock already has 8.5 million sunsets by some very talented contributors. To succeed in this category, your work must be outstanding.