They will be in the coming decades as the population ages. The direct and indirect effects of sitting all day long are going to be incredibly costly to the society, and the only reasonable policy would be to combat our car addiction by any means necessary – and this is even distegarding all the other disastrous externalities of widespread personal car use!
Modern “western” people spend a tremendous amount of time sitting - either in an office or a car - and are almost totally sedentary.
In fact, so sedentary that the mere act of walking is considered “exercise”.
Frankly, I’m surprised the mental and physical outcomes aren’t even worse.