When I was young, I needed to shampoo every day. Usually showered daily too, and in the hot summer, 2x’s per day.
Now that I am older, it really is not necessary to shower daily, so it is 2 or 3 times a week - except when summer is here, I may require daily. Also, if doing yard work, it makes a difference too.
Common sense rules here.
Bad news: you may think it's not necessary to shower daily, but it still is. You may not be aware of it because olfactory acuity declines as we age, which means we can't smell things as well. Unfortunately, at the same time our innate stinkiness increases as we age, too. You may be offending those who are younger and have more sensitive noses, especially females (since females in general and pre-menopausal females in particular have more sensitive noses than males do).