I think he compared Deakins to Dicaprio because they are both generally regarded as masters of their individual crafts. That isn't to say that the effort they put in, or they are similar in any other way to each other, just like comparing two dedicated workers, it was a harmless line.
It is stereotypical and explains Japanese life in a "tourist" sense because we are from the perspective of tourists. The character Charlotte is visiting tourist attractions in several scenes, and even Bob goes golfing on a beautiful course as you saw. The film is about isolation, and therefore Tokyo, and the exaggeration of its oddities is to emphasize how even if the characters were in a familiar environment, they would still be isolated and alone. Tokyo is Sofia Coppola's vessel for the metaphor of isolation. Strange places, massive amounts of people in a single space, all contribute to the idea of a specific 2 people that met in a strange circumstance that culminated in a perfect storm of friendship and resolution.