I've been wondering about this. I assumed our senses sharpen at perimenopause as some friends in their early 40s said similar recently.
Or pregnancies have a lasting change on sensory processing?
Or the trend for natural deodorants is still ongoing...
It could be result of overcrowded homes, fuel hikes, poverty eg less hot water, cold rooms, washing/drying clothes less often to save costs, lack of space to dry clothes indoors. Houses with no spare rooms, or cramped house shares?
Increase in mental health problems, harder to access treatment. It's very common for people to neglect personal care when depressed, chronic anxiety, lack of motivation.
Bad diet could play a role too. Obesity rates going up, so people sweat more, prone to weight-related health conditions. Which in turn may make it harder to wash and dress, especially washing hair.
The average family has less time these days. Parents usually both employed, fitting a commute around kids' school/nursery run, trying to get everyone's laundry done at weekend. Maybe it's hard for many to shower every day or wear a fresh outfit, even if no issues with money/health/mobility?