First your white balance is off. The picture is to bluish (cold).
Second there are artefacts in the picture. That is related to the camera you used. As phone pictures are not elimiated per se, they still need to meet the same quality requirements than other cameras. The small sensor, however, makes it difficult to deliver that quality.
Third, I think that the sky is blown out.
ABAMBO | Hard- and Software Engineer | Photographer