My goodness, no it isn't essential. I shower most days, but on some days have a good wash, especially if I am staying in. People didn't smell years ago when showers were rare and hot water wasn't available all the time. Bathing once or twice a week was the norm and people shared the bathwater. We washed down at the sink with a flannel and soap. To be honest too many showers,especially using products can destroy the balance of your skin.
I haven't had a shower today and I don't smell!! People are obsessed with hygiene these days!, both personal and in the home and they aren't healthier for it.