I grew up in Germany. For the past 13 years, I've lived in the US. Oh, how I wish I could go back to the "day in day out, everyday in public transit" instead of this car hell. In Germany, just like in Japan, I didn't feel that it was noisy at all. It was clean and quiet and soothing, I could just sit there and relax. Everyone takes public transport, across all income ranges.
As a result, public life itself is more quiet and soothing, because you are not constantly surrounded by cars, even if just sitting outside a café.
As for the family you stayed at, they must eat differently from the Japanese families I know personally. Studies agree: https://www.livescience.com/54133-japanese-diet-longer-life.... https://chns.cpc.unc.edu/resources/publications/bib/2884/