Hasakane, your DS sounds lovely. My DTs have an obscene amount of toys that I am slowly whittling down via freecycle. None of them have kept their interest for more than 5 minutes at a time. They are happiest when doing things with me or with each other. Absolute favourite activity is going on walks with the dog, followed by playing in the park or garden (slug spotting is the highlight of the day at the moment), reading comes in third. DD (2.4) is rather like your DS. I jokingly refer to her having OCD as she not only puts things back where she got them from, but actually pats the drawer/box/whatever after doing so!
If anything, your little boy sounds quite advanced for his age, so I wouldn't worry too much about his development. As long as he is interacting socially with you, he will be fine. Social play and development is far more important IMO than the ability to play with toys. After all, our ancestors never had the luxury of lots of toys or TV or anything...