You are right , no one needs a watch if they have a phone but I do like wearing a decent one , makes me feel properly dressed . I accept not everyone shares my view.
Always wear a Rolex datejust - on my 4th one since I was 18 . I part exchanged the first 2.
In Manhattan especially the upper east side , everyone looks at the watch you are wearing . Some people there will spend the same on a watch as a new BMW it’s crazy .