Could it be that my hair looks more coarse?

It is possible that you are using too much shampoo and that the water is too hard, which is not good for the skin or the hair. Calcium in the water can cause the active ingredient in the shampoo to settle on the skin and hair, dissolving the protective (oil) layer of the skin and hair. It is best to install a water filter because the skin may develop atopic dermatitis and eczema and the hair may become rough and dry. If you cannot install a water purifier, wash your hair less frequently and use less shampoo.

Would you like to do the test? Take an empty water bottle and fill it halfway with tap water. Then add 1/3 real soap (for cleaning the floor, not dish soap) and shake the bottle well. If the foam rises to the top and the water is clear, the quality is good. If the water becomes cloudy, the water is too hard and must be treated.