In one bathroom, we have a built masonry shower wall with a shampoo niche or Schampus niche. We definitely considered adding a second niche at the bottom just for shaving, like in the picture. I wouldn't want to miss the existing niche.
If I were to build again, I would include a slightly sloped (just enough for the water to drain) seating area. At the right height, it can be used both as a footrest and as a seat for "showering together" or whatever positions you can think of. A sturdy grab bar in the shower is not only for seniors; young couples sometimes also spontaneously appreciate such holding options in the shower.