I think the roads in Tokyo or Yokohama are narrow so there are no place to make benches. More, if we make public seating in such cities, the young may stay there and it become hindrance and more difficult to get thorough the road.
In my opinion, Japanese people doesn't become familiar with being looked by someone while they are seating. If there are benches at city road and someone sit there, I watch them unconsciously. However, I feel uncomfortable to sit at conspicuous place and don't want to be watched during a break.
I want to sit without paying money but it's difficult in Japan especially in a big city because of that reasons.